Launched today, Windows 8 Release to Manufacturing (RTM) offers only minimal changes to June's Release Preview version, including new graphics (what Microsoft calls "tattoos") for the Start screen and Lock screen backgrounds and interface polishing for some of the Windows 8-specific apps that ship with the operating system. In addition, there have been a variety of bug fixes and performance enhancements, as well as some minor tweaks to the operating system's look and feel.

Apart from that, though, Windows 8 remains essentially the same: a two-headed operating system featuring a new Windows Phone-like tiled interface and Start screen (once called Metro, but now apparently called simply Windows 8) as well as the traditional Desktop interface. As with earlier preview versions of Windows, these two interfaces uneasily coexist, with the new Windows 8 interface better suited for tablets and touch devices, and the Desktop the better choice for desktop PCs and laptops.

The Start screen in Windows 8 RTM hasn't changed much from the Release Preview.

I tried Windows 8 RTM on a tablet that can do double-duty as a traditional PC with the addition of keyboard and mouse, and tested it in two ways: solely as a touchscreen tablet and solely as a traditional PC.

As a tablet interface, Windows 8 serves its purpose beautifully, its large tiles with constantly changing information inviting interaction via touch. Designed from the ground up to display information, it provides a significantly different experience from using an iPad or Android tablet -- information-centric rather than app-centric. (While Android widgets do offer live information, they're much smaller than Windows tiles and feel like an afterthought to the bounty of apps that typically take up the screen.)

Windows 8 falls short on tablets only when you want to get to the Desktop, but considering that tablets are generally used to consume content rather than create content, you likely won't need to go there.

But Windows 8 on a traditional computer still feels like a kludge, because the Windows 8 Start screen and its apps feel more natural with a touch interface than a mouse-and-keyboard one. I found myself continually bypassing the Start screen to get to the Desktop, and then once I was there, frequently looking for the dearly departed Start button, which no longer exists.

The Windows 8 native apps themselves are beautifully designed, though. Even on a traditional computer, some of them, such as the People app, are useful. But others, such as Mail, remain underpowered compared to traditional desktop apps like Outlook.

What's new: Small 'fit and finish' tweaks

There have been no major changes in Windows 8 RTM compared to the Release Preview. One minor change, though, appears the moment that you boot into the OS: There's a new default lock screen background showing the Seattle Space Needle, a lake and mountains. There are other arty new lock screens available on the PC Settings --> Personalize Windows 8 screen. Similarly, there are new designs for the Start screen, many of them complex and baroque-looking. In all, Microsoft says there are 14 new ones.

Windows 8 RTM features a new set of backgrounds for the lock and Start screens that are artier than those in the Release Preview.

Windows 8 RTM also has a new, moderately useful tool for switching between apps, but only for touchscreen devices. If you swipe from the left edge, you'll switch to the most recent app you had been running just before the current one. This not only works with Windows 8 native apps, but also with Desktop apps. To control whether this feature is active, go to PC Settings --> General, and then toggle "When I swipe in from the left edge, switch directly to my most recent app" on or off.

It's now also slightly easier to search through the Windows Store. When you're in the Windows Store, you can simply start typing to initiate a search, the same way you can on the Start screen. Previously, you could only use the Search charm, the built-in tool for searching through Windows apps and files.