The main thing to ask yourself before buying anything is, will I need it?
You may go guitar shopping and find a beautiful instrument that plays nice, has a nice finish, good pickups - the whole nine yards. But it's Floyd Rose. What do you do?
Well, you need to figure out how much you're gonna use that thing, if at all. If you're not going to use it, or not use it that often then I suggest not getting one. I have one on my guitar, and let me tell you it is a headache and a half.
..but I use it.
There are good things about them, though. You can do divebombs or screaming harmonics, you can do surf guitar vibrato, finish off a song by dragging the notes down until they don't sound anymore...the options are many and the results are very good.
Tuning is a hassle, though. Forget alternate tunings!
So is it worth all the trouble? Eh, kind of. I will say I am happy I have another guitar without one.