I've been using Windows 7 for about a week now, and I have to say -- it's pretty sweet. This is my completely subjective review.
Windows 7 makes my computer feel faster. I'm not running on the fastest hardware here -- I've got a 2.4Ghz P4 with 768MB RAM (the minimum specs call for 1Ghz and 1GB). With XP, it takes an age to get to the desktop, and even once you can see the desktop it takes a long time for it to actually be usable.
With 7, it starts up in roughly the same time, but the desktop is usable as soon as you can see it. While this feature was new in Vista, my computer doesn't spend ages on the "preparing your desktop" screen I have seen on Vista computers.
Using Windows 7
Applications load snappily in 7, and I have yet to see the freezes that sometimes occur in XP. I can't decide whether to put this down to 7 or the fact that it's just a new installation -- time will tell.
The best thing I can say about it is that there's nothing really bad about it. I like the little improvements, like how when I drag a file it explicitly says "move to..." and "copy to..." rather than rely on an icon. I like how when I minimise an application that's doing something, it displays the progress bar in the application's thumbnail in the start menu (I don't like how it takes focus when it's done). I like how I can set my desktop backgrounds to rotate through pictures, and I like that there's localisation features in the built-in themes (in the US at least, it'll show you a different background depending on where you live).
There's definitely a lot to like about 7. But, there's one thing I'm not sold on.
In 7, Microsoft has decided to go a bit OS X-y and has turned the taskbar into more like a dock. Instead of having a separate window for every application you have open, you just have an icon for every application. Clicking that icon lets you visually choose between the different windows your application has open (and in Internet Explorer's case, the different tabs it has in all of its windows). This means I can't quickly see how many windows I have open (something I found myself trying to do when I was wondering which window a site I had opened was in).
I guess it's not really bad -- it's just different and new, and I haven't gotten used to it yet. It's interesting though that this is the only feature that I haven't loved at first use.
When you look at the entire product, there's not much wrong with it. It hasn't crashed once (remarkable, from a beta), it's fast, it found all my device drivers, and there are several new features that are great.
The Windows 7 beta is what Vista should have been. While it looks like Vista in many places, it doesn't get in your face like Vista sometimes does. I may or may not have User Account Control turned on -- the key thing here is that I don't know. That pretty much sums it up: this version of Windows gets out of the way and lets you do your work, and that's the best compliment you can pay an operating system.
It would be remiss of me not to mention that the end-game effects in Solitaire and the other games have changed. In every previous version of Solitaire, the cards would bounce around and fill up the screen. Now they fall down from the top and shatter on the bottom. The other games, like Spider Solitaire, still feature the fireworks, but now they're 3D and pretty.
My games reviewer, Leah, would like it known that the Solitaire effect is not as good as the old one, but that the fireworks are much better.