I'm a bit late, but...
Anybody who is reading this post now, who is either not on lion yet or having issues now, here is my advice. (May 2012)
Currently Lion is in version 10.7.4. This means all bugs should have been fixed, right?
Unfortunately to me I have had endless problems with Lion. I am a professional (I work at a movie studio) and I upgraded my computer just recently to lion so I could use Air Drop with my colleagues (I thought it would be great to just drag and drop video and audio and all other kinds of files). Also scroll bars are gone now! I got them to show but they are barley visible and there are no little arrows to click. Thirdly, I have had tons of performance issues (lots of beach balls!

) Also my fan is on non-stop even after a power reset! Overall I am unhappy with Lion. If you are still on SL, STAY! Lion is terrible and I just can't stand it.
Another note, I have used Mt. Lion (My friend is a developer and has it) and unless you use your iPhone endlessly, don't even bother! SL to me is still the professional copy of Mac OS X.
Sorry for my ranting but I am very angry at Lion! Not to mention, I have not been happy working late to re-edit footage that Lion lost for me. (Never had a problem in SL) Lion has lost more work for me in 1 week than I have in about 8 years of using Mac.
Sorry Apple

but, I am unable to use Lion any longer! Cue the Snow Leopard Install Disk that came with my Mac!