i am rooted and lt me start by saying, it is addicting. you download and flash roms so much, it's crazy. once you get into it, it's hard to stop.
pros:
-flash awesome custom roms and radios like das BAMF and TeslaCoil
-make nandroid backups
-take screenshots with ease
-flash a kernal to save battery or to make your phone really fast
-say your rooted and join the awesome community of folks at XDA!
cons:
-hard to say, I havent had any!

-the only possible things are that you get more down and dirty with android. if you aren't comfortable with possibly making your phone a brick, rooting is not for you.
I rooted and am 100% happier then when I had stock sense.
hope this helped in your decision!