So far, my experience with Windows 7 has largely been a positive one. I’m enjoying the new taskbar and all of the new “shiny” UI. (Note also that I was running Windows XP before switching to 7, so I wasn’t using Aero with Vista prior to using Windows 7)
One bug I have noticed that drives me crazy is the navigation pane bug. There have been several reports that others have filed indicating that this is not new, nor is it isolated to just my machine. I have been able to consistently reproduce this bug with “Automatically expand to current folder” option on or off, so I don’t believe it is involved with the bug. I have created a Problem Steps Recorder file, and a youtube video showing the reproduction of this bug, hopefully this helps to resolve this issue.