Update 5/15/15: I've clarified some of my findings at the bottom of this post.

I've owned the 2015 MacBook for just over a month now. I've had a remarkably good time using it so far, and just yesterday I decided to upgrade my installation of Windows 8.1 to the Windows 10 Insider Preview. I had tried it out a couple months earlier through a virtual machine, and at the time I wasn't sure I wanted it as my main operating system. But after taking the plunge, I'm very happy to be using it. I wanted to record a few thoughts about it for others curious about the new OS, especially its usability and performance on this new hardware.

Setting up was easy. I opted to install from Windows 8.1, which still installs a fresh copy of the operating system, but it's easier than creating installation media from scratch. I did, however, make sure to re-download Apple's latest Boot Camp drivers through Boot Camp Assistant before installing. These saved to an external USB drive that I left plugged in during the installation. Things proceeded typically. If you've ever installed Windows 8.1 on a Mac, you'll recognize the process; not a lot has changed. Fortunately, upon finishing the installation, the Boot Camp drivers were automatically recognized on the USB drive and installed, which is what is supposed to happen. Unfortunately, not every driver installed successfully the first time around. For example, I was able to modify volume with Apple's native UI popup, but brightness (which uses the built-in Windows switcher) didn't change. The all-important system tray application for modifying trackpad settings and quickly booting back into OS X also wasn't present. I rebooted and chose to re-run the driver installation after "troubleshooting compatibility", where Windows recommended that it skip the forced version check. That fixed things. Apple still curiously doesn't provide a Bluetooth driver in this driver package, but everything else works.

Years ago I discovered Trackpad++, a driver solution to bring the functionality of Apple trackpads closer to how they behave on OS X, and closer to how high-end trackpads now behave on Windows. I didn't actually have it installed on my old Mac's Windows partition, but I highly recommend installing it now. The developer's website looks straight out of the 90s and not terribly trustworthy, but he has a strong reputation, and the driver was recently updated for the 12-inch MacBook and Windows 10. You'll also need to install another application to allow the new trackpad driver to be installed, but it's worth it. With Trackpad++, I have three finger drag, two finger swiping for forward/back, as well as two finger swiping in from the edge to access the new Notifications pane. I even have four finger swipe access to Task View, (just like how I access Mission Control on OS X), which may be my favorite feature in Windows 10.

Continuing to move in, I realized that Windows 10 was kind of gorgeous. Little design touches have really improved the way things look, such as the switch to circular account pictures on the login screen. I found that I had to switch desktop scaling to 150% for the size of everything to be just right, but that was a nice compromise between readability and screen real estate. As is typical of high DPI screens on Windows, not every application scales natively right now, causing some to look blurry. Steam is a notable example. But many things are now upscaled, such as Microsoft's desktop OneNote application, and generally things look great. The same thing happened on OS X when Retina displays were first added to Macs, but obviously Windows has a larger variety of software, and much less forced adoption of devices with high DPI displays. In time, most everything will be revised to take advantage of these nicer screens, but I do wonder if legacy applications that have long since stopped receiving updates will just be blurry (or super small) forever.

Microsoft Edge, the new name for Project Spartan, is an absolute champion, even at this stage in development. It's rough around the edges, with no ability to change the search engine away from Bing, and no History feature at all. But those feature will come in time for Windows 10's release in August. Edge was fast to render pages, and it handled a large number of tabs admirably. Especially after the announced extension support, I definitely see using this browser when the final version is released.

I should also amend my review of the MacBook to state that some 3D games actually perform pretty well. I was able to keep Left 4 Dead 2 at a near-steady 60FPS running at 1280x800 and medium settings. Things occasionally slowed down by ~10FPS when there were a lot of enemies on screen, but I was legitimately impressed with how well it looked at that resolution and those settings. Had I dropped the visual settings to absolute minimums, I bet the frame drops would have disappeared.

I also was able to emulate Super Smash Bros. Melee with Dolphin at a steady 60FPS. And, of course, a 2D game like Super Meat Boy ran beautifully well at full Retina resolution, having no problem playing at full speed. Overall, gaming isn't guaranteed to be good on this machine, but the spectrum of PC game performance is just massive, and I failed to account for that in my original review. Some games, like Valve's Left 4 Dead 2 (and similarly Dota 2, which I've heard runs very well), are produced by a developer that prides itself on optimization and efficiency, even on poor hardware. Others, like Dishonored and Cities: Skylines, just aren't designed with integrated graphics in mind. (In Cities: Skylines' case, the developer acknowledged this shortly after release.) I'm happy that I revisted 3D games on this machine, because now I have a rosier outlook than before.

The biggest struggle I had in Windows 10 was getting the above screenshot. Without a PrintScreen key, I had to download some software to let me take a timed screenshot. One thing I miss from OS X is the Cmd+Shift+3 shortcut. However, the above screenshot represents the sort of multitasking that was easily achievable. I'm impressed with performance.

Elsewhere, things are great. Cortana is an excellent addition, and I think it's only a matter of time before Apple rolls Siri into OS X somehow. Being able to say "Hey Cortana, what's the weather going to be like tomorrow?" from across the room is really, really cool. Battery life seemed very good from the short time I used it. I didn't fully deplete the battery, but I was on track to get over 9 hours of use with brightness at 40%. Mac battery life is rarely as strong on Windows, but there doesn't seem to be as enormous of a gap here, which is good. Then there's Task View, Microsoft's answer to Mission Control, which is excellent. It behaves like Mission Control does on OS X, meaning it displays all open windows, as well as simulated desktops. This is an absolutely fantastic feature.

Here's the real kicker: it's fast. It's smooth. It renders at 60FPS unless you have a lot going on. It's unequivocally better than performance on OS X, further leading me to believe that Apple really needs to overhaul how animations are done. Even when I turn Transparency off in OS X, Mission Control isn't completely smooth. Here, even after some Aero Glass transparency has been added in, everything is smooth. It's remarkable, and it makes me believe in the 12-inch MacBook more than ever before.

So maybe it's ironic that in some regards, the new MacBook runs Windows 10 (a prerelease version, at that) better than it runs OS X. But it's a testament to two things: Apple's fantastic MacBook hardware, which is forward-thinking yet surprisingly agile; and Microsoft's excellent Windows software, which entices and excites with its beautiful interface, useful new features, and rock-solid UI transitions. I'm excited to keep Windows 10 installed on this machine, both now as a preview, and later once the final version is installed. Even hardened OS X diehards owe it to themselves to give it a try.

Update 5/15/15: The response to this article has been astounding, and I really appreciate all of the feedback I’ve gotten on it. I want to do my best to clear up a few specific points that I originally glossed over in the original piece.

First, OS X on the MacBook exhibits UI stuttering even at the non-downscaled resolution of 1152x720. This resolution causes things to be laughably large, and I doubt many use it, but it is necessary to take into account. Otherwise, it could lend Windows an unfair advantage, as Windows doesn’t use downscaling to manage UI resizing. I mentioned this in my review, but I did not reiterate it here.

Second, I was a bit vague about the difference in performance between Mission Control and Task View. Task View does slow down to less than 60FPS, and that can happen when only a handful of applications are open, not just when “a lot is going on.” It does, however, seem to have a higher tolerance, performing better per number of windows open than Mission Control. It is difficult to compare these two operating systems fairly, because Windows 10 is still very much beta software, and sometimes it has slowdowns that don’t seem otherwise characteristic of its performance. For example, sometimes Task View has a slight delay before running, but so does the Start Menu. Windows 8.1 does not exhibit this. Other times, Task View and the Start Menu respond without delay.

I cannot guarantee that Task View often runs at 60FPS, as I haven't yet found a working measuring tool, but to my eyes, there are no stutters or frame drops in the super-smooth animation. In other words, it looks like 60FPS, and it looks much better than transitions on OS X. I want to quantify this claim. and I am still looking for software that will track UI performance on Windows, but with Quartz Debug, an OS X profiling tool, I found that Mission Control hovered around 41FPS for 720p and 37FPS for 900p, the latter of which is ideal for screen real estate. Because Apple does not cap Mission Control at 30FPS or something else, and because inertial scrolling and Space-switching more frequently operate at 60FPS, it is reasonable to assume that Apple expects Mission Control to be able to reach 60FPS too. Thus, framerates in the high 30s and low 40s stick out.

Until thorough benchmarking is completed by me or someone else, I think the best way to put it is this: Task View often runs at 60FPS, while Mission Control never runs at 60FPS.

Overall, UI speed is only one metric of speed, and articles claiming that I found Windows 10 to be faster than OS X are missing the point. My initial impressions of Windows 10 were very good, and for those who are able to test both operating systems themselves, it should be evident that Windows 10 appears to have a higher tolerance for smooth UI transitions than OS X does.