I've been running windows 7 for about a month, due to being part of MS technet, developers got the full release of windows 7 early. I'm running Windows 7 Ultimate 64bit on an older laptop :
- Dell E1705
- 4 gigs ram (3.25 addressable)
- Intel Core 2, 1.73GHZ
- Windows rating experience : 3.7
So far there is not a single piece of software I've been unable to run, from Visual Studio 2008, Adobe Flex 3 & 4, Directory Opus, Photoshop CS4, Adobe Flash, Filezilla, Charles, Enterprise Architect to name a few.
The only thing I could not get to work was the new sprint Franklin card that does the 3g/4g, however my business partner Paul has clear 4g card working under Windows 7 with a bit of driver version switching (not running the latest drivers).
In use, Windows 7 is what Vista should have been, its fast, responsive, I'd say at least 30% faster on lesser hardware than Vista, All the new features like live preview of application windows by rolling over the application in the start bar are nice, but truly the fact it just works, its fast and it doesn't hang like vista did is what makes it better for me. I am especially happy with the drive upgrades/installation and how seamless it is and I don't seem to have to go downloading a driver very often, windows finds it, so their integration with vendors driver libraries has been much better.
I would highly recommend switching to Windows 7, if you're currently on the fence.