First install
I downloaded the public beta of Windows 7 at the weekend. I am running the 64-bit version on an Intel i7 system.
The install seemed to take as long as Vista, not really noticeable change here. Once installed hardly any of my system devices had drivers. I guess this is fair enough considering i7 systems are fairly new. I had to manually install the drivers for most components of my Asus P6T.
Repeated BODs
I would not recommend running 7 if you intend to use an abit AirPace Wi-fi card! Windows 7 did not recognise this device even after installing the "Drivers" from the CD that comes with it. Don't you just hate it when hardware manufacturer's make you install their application and don't just put the stand alone drivers on the CD?
When I updated the drivers for the Wi-fi card using windows device manager I was given the Blue screen of death. This happens everytime. I had to get another card.
Usability
I have to admit Windows 7 is fast, very fast in fact. I love the maximise and restoration of windows, its a nice touch. I haven't got the hang of the task bar yet, its very different.
They have done something weird with the UAC prompts. Sometime I click on buttons/links with the shield (e.g. device manager) but there is no UAC prompt. It is not disabled as it does work for different controls. I am actually enjoying this as it's less obstructive.
Issues
I can't say that this build is a stable one. My system hangs at least once a day and I mean a proper hang where Num Lock does not light up and a hard reset is needed. This system has never hung when running vista.
Windows 7 comes with Internet Explorer 8 which is a real pain. IE8 crashes more that windows 7, about once an hour. It does have a nice feature to "restore your session" after a crash where it restores all the URLs of your tabs, it would be nicer if it didn't crash in the first place though. Obviously your session is dead on the web server at this point so you have to start again anyway. I have also seen quite a few popular websites fail to render on roll over events.
After several IE8 crashes I installed google chrome, however it turns out that doesn't work either. Google chrome fails to render any pages at all, but its ok because its a "known compatibility problem" with windows 7, hmmm.
Back to Vista
For now I will be booting into Vista to get stuff done and Windows 7 when I want to play with new features. In my opinion the Windows 7 beta is just not in a usable state, for now, but at least World of Warcraft works in 7.