Caps lock is good!
Windows key might be REALLY annoying when:
-Playing game in full screen-
Evil Boss: AH HA! I WILL KILL YOU
Me: You wish, all i have to do is press alt
*Evil Music starts*
*Boss shoots about a million times and missed all of em*
Me: Now to win!
*Goes to press alt key*
*To busy dodging shots so hits windows key by accident*
*Game minimises, goes to desktop*
ME: AH!!!!
*Reopen <You have died>*
Me: OMG! FFS! GAH! AH!
On the other hand, it is a quick and easy tool to use to get back to desktop when a game freezes.
I give windows key 3/10 xD