There’s something magical about the touchpad on a MacBook. Out of the box, the first time you use it, it just works. Built out of a big slab of glass, the surface offers just enough friction for optimal finger sliding. Whether on the MacBook Pro or the Air, the trackpad is masterful at figuring out multiple finger inputs, it’s brilliant at disregarding errant touches, and it’s got a knack for multitouch gestures. The best thing about the Mac’s touchpad is that you never really notice it’s there. It’s designed to be invisible; everything you do on it feels natural and intuitive, and after a while the on-screen pointer becomes something like an extension of your fingers.

It’s precisely this so-good-you-don’t-notice-it sensation that leads people to take the MacBook’s touchpad for granted, to overlook it as a chief selling point for Apple’s notebook line. As I’ve written many times, I find the MacBook Air to be one of the best personal computers ever built, and certainly the best all-purpose notebook computer on the market today.

Every time I praise the Air, I hear from an army of Windows dittoheads who accuse me of being in Apple’s pocket. They point to articles like this one, which note that on a spec-by-spec basis, you can find a number of PC “ultrabooks” that appear to best the Air. For instance, both Toshiba and Acer make machines that weigh less than the Air. Some ultrabooks offer discrete graphics chips for better gaming performance, while others come with bigger screens, brighter screens, and better resolution. Finally, many PC ultrabooks cost a couple hundred dollars less than the Air. Given all these apparent advantages, these Mac haters argue, only a fool would choose an Air over the competition.

The truth is, I’m not opposed to using a Windows laptop. I actually find Windows 7 to be superior to the Mac OS. My desktop—my primary computer, a machine with which I spend more time than I do with my wife and son—is a dazzling Win 7 beast that I built myself. But I switched to Apple notebooks more than five years ago, and I did so precisely because of things like the trackpad. I’ve searched high and low for a Windows notebook with a touchpad that comes close to the buttery bliss offered by the MacBook line. I haven’t found it, and you won’t either. At best, you’ll find a trackpad that can perform satisfactorily after you tweak a lot of settings—which may work fine for pros, but it’s not the kind of just-works experience that most computer users want.

Why does any of this matter? Because PC makers’ inability to build a perfect trackpad is symptomatic of the larger difficulties the Windows device business faces in the mobile age. Windows device makers are used to competing on specs; they buy commodity parts, they use generic reference designs, and they stick everything together in a case and slap on an inscrutable model name. This worked perfectly well in the desktop market, and for many years it worked well in laptops, too.

But when you move away from those machines into computers that are more like appliances, you get the sort of clunkers that now clog the ultrabook market. They’re cheaper than the Air, they have better specs than the Air, and yet—because of things like terrible trackpads—they fall far short of the Air.

The touchpad problem illustrates why Microsoft had to build the Surface rather than let its hardware partners take the lead on Windows 8 tablets. Making a great trackpad isn’t easy. Humble as it seems, perfecting the interface depends on a host of skills that most companies don’t possess—top-notch industrial design, perfectionist control over manufacturing processes, and, most importantly, software that’s finely crafted to work with the hardware. If PC vendors can’t even get this small thing right, how could they possibly make something as polished as an iPad?

To understand how much trouble PC notebooks have with touchpads, look at the Asus Zenbook, an ultrabook that’s often hailed as the next-best-thing to the Air. The Zenbook matches or beats the Air on most specs, and a slew of tech reviewers have given it high marks. The Wirecutter’s Brian Lam, who calls 13-inch Air the “best overall laptop for most people,” recommends the Zenbook Prime UX31A as something to consider “if you really hate Macs.” CNet gives the Zenbook 4 stars (out of 5), while Laptop Magazine named it an Editor’s Choice and “the best ultrabook.” Intel sent me an 11-inch Zenbook a few weeks ago, and I’ve been struck by two things. First, Asus has done a lot of work to make the machine look and work just like the Air. Second, by not putting much thought into the touchpad, the company blew it.

The Zenbook’s touchpad is the opposite of the Air’s—everything about it is laborious, requiring careful, frustrating choreography to accomplish even though most basic actions. The machine gets confused with multiple fingers; when Anand Lal Shimpi reviewed a Zenbook last year, the cursor got stuck when the touchpad detected both his thumb and index finger at the same time. Ars Technica’s Casey Johnson wrote, “Dragging and dropping is particularly infuriating. Once you put that second finger on the trackpad, the trackpad almost immediately forgets which finger clicked and which showed up to drag; often, the cursor will jump across the screen to the finger you just put down to drag.” Several times, Johnson noted, the trackpad’s unpredictability caused her to highlight and delete entire blocks of text.

Asus has since updated its drivers to improve the touchpad. Shimpi says the newer version is “pretty good, albeit not quite perfect.” (Among other things, “the pointer will occasionally refuse to move, but it’s very rare.”) Others say that if you turn off a bunch of settings, the Zenbook’s trackpad is OK. “At first the cursor was too unwieldy, especially when typing, and we would accidentally type over our work,” says Laptop Magazine. “However, once we disabled both tapping and drag and drop in settings, the UX31A was less temperamental.”

My own assessment was similar. If you fiddle around with the software, you can get the Zenbook’s trackpad to work maybe 80 percent as well as the Air’s. But that’s as close as you can get—and that missing 20 percent, which includes things like consistent two-finger scrolling, makes all the difference in the world.

Why is the Zenbook trackpad so bad? Probably because it’s a blend of several companies’ hardware and software. At first, Zenbooks shipped with touchpads made by two different vendors—Sentelic and Elan. This caused inconsistent experiences across the product line. People who got models that included the Sentelics touchpad noticed many more problems than those with the Elan pads.

But if you had trouble, you had to figure out which touchpad was baked into your device. This was a headache. Asus support staff had to monitor Amazon reviews, and they were personally responding to customers with gibberish like this: “Please check your Device Manager and verify if the touchpad is Sentelic or Elantech. If it is Elantech, it will show that it is Elantech. If it is Sentelic, it won't show the name but rather will just say General or something along those lines….”

Seriously.

After a few months Asus began switching all its Zenbooks over to Elan touchpads, and it now ships a software utility made by Elan that allows people to tweak their touchpad settings. But as Shimpi points out, this can only get Asus so far. If it really wants a perfect touchpad, Asus will have to write its own software to better integrate the trackpad into its machine. “At some point it may just come to that,” Shimpi writes.

I know what you’re going to say: You’ve got a Windows laptop and your trackpad works perfectly. The Zenbook is an exception. Other PC laptops aren’t so bad.

I don’t believe you.

But even if you’re right, I’ll bet that there’s something else about your device—maybe it doesn’t respond from sleep very quickly or consistently; maybe it doesn’t boot up very fast—that causes you endless annoyance. More often than not, those problems are caused by too many cooks, by a lack of tight integration between all the hardware and the software in your machine.

If you want perfection, you need a single company to design everything from touchpad on up. Microsoft, finally, is coming around to this truth.