So, I've installed Windows 7 last night. I had to repartition my machine, so that I could dual boot with Vista. I repartitioned using Vista's Disk Management, which was quite easy.
The installation itself took about 20 minutes, which was very fast! My experience so far is very positive. I have played with it at work, but even with a few minutes of experience in day to day stuff, I already found out one cute UI improvement. When you download a file using IE, the IE icon on the new task bar turns partly green, to show the progress of the download. That way you don't have to check the download window to see how the download progresses. Here is how it looks like:
Anyway, I'll keep updating on my experience. Hope it will be positive all the way!