I installed Windows 7 Beta in January. I used my laptop that's just been sitting around since I finally bought a gaming rig. So far, I am impressed. It's as if they put Vista on a treadmill and made it lean, mean, and it sweated out a lot of junk.
As for the famed UAC, I haven't heard a peep out of it except once when installing Avast.
The hardware I'm using is from 2006. It's a Dell notebook.
-----------------------------------
Dell Precision Mobile Workstation M65
Intel Centrino Duo T2600 2.16GHz
2 GB RAM
Nvidia Quadro FX350M 256 MB graphics
200 GB 7200RPM HDD
-----------------------------------
Installation was a breeze, under 30 mins, and it even downloaded and installed the correct and current drivers for all the hardware (!). Instead of having to reformat the drive it moved all of the old contents of the drive to a folder called "windows.old" so that you could access all your old stuff even with a "clean" installation.
Next was Office 2007.
Tried installing Adobe CS2 for Windows, that did not go so hot. The installer caused very strange behavior and only partially finished before dying. At that time I did not know CS2 is not compatible with Win Vista, and therefore will not work with Win 7. I have no reason to upgrade to CS4 yet, so shucks.
Installed games that I know for sure worked well with high FPS when XP was on there, so we'll see how that goes. This includes Half-Life 2, Halo, Call of Duty 4, and Fear. I am getting the performance I expect, if not more.
After copying all my music out of "windows.old" and putting it in the provided Music folder, I didn't have to tell Media Player to look for new music. It did it all on its own and FAST. I opened media Player and it was all there, album art included. Even scrolling down through all the albums was great. XP would lag a little bit as the album art loaded while scrolling down, but Win 7 flies through it all.
Search is incredibly fast. Just start typing something and it will already have found it before you're done. This is surprising because the file system Win 7 uses is still NTFS - which is a fine file system, but MS was and still is developing a more advanced file system that has become known as WinFS. This was supposed to go with Win Vista but MS put it back in the incubator.
In summary, I believe Win 7 is very stable, lightweight, and fast - faster than XP --- which it SHOULD be! Vista was like one step forward in design and two steps back in operation. Win 7 (so far) is nothing but forward in my humble opinion. Last week I switched the theme to Win classic, shiny interfaces do nothing for me, including Mac OS. You could say I'm pretty utilitarian.
What does this mean for Microsoft? It means that with Vista they are repeating their past with Win Me (what a disaster), only to come out with something better a bit later. Will it convince mac users to switch? No. Just like you won't get a Pepsi person to switch to Coke, these two OSs have their fans and die-hard backers. Windows will always have its appeal since it will run on practically anything. Heck, I run windows 3.1 on my toaster. Mac OS will always have its appeal: sleek, refined, and just georgeous. But in the end, does a photo turn out better edited either one, No.
I see Win 7 as a"win" for Microsoft, although I was highly expecting WinFS to be incorperated. The way they are rolling this OS out in beta to the public is awesome. Any little quirks you notice, you can send up a comment, and likely there will be a stream of updates coming down the pipe every day you shut down. Hopefully by the time they can say the beta is done cooking on the hundreds of thousands of PCs running it, it will be done enough for all who want it.
I am sure there are some on this forum that only see snake oil when they see Windows, but to those I say: open your eyes.