This game is not that buggy. It's pretty stable, though like pretty much all PC games you should expect problems now and then. I've had it freeze on me a couple times.
Having said that, SR3 was lots of fun, though some SR2 fans were unhappy with the more silly direction SR3 took.
They're both very different games, though...it just depends on which sort of game you prefer, though you could always get both. --- It is a capital mistake to theorize before one has data. ...one begins to twist facts to suit theories.... Sir Arthur Conan Doyle