First things first: the Ultimate Sith (Collectors) Edition is the only version released for PC. Second, I have had the experience of owning the original (non-collectors) version.
This is a great game for playing as a Jedi (or Sith in this case) and unleashing dark force powers on your enemies. It isn't as good as the Jedi Knight series, but it is more recent. The load times are ridiculous, the target-lock is not that great and all instructions on which key to press show default key always, even if you change them. But if you get beyond that it is a really fun game.
If you don't own the original, you will have a fun time slashing, zapping and throwing enemies around, even if the story isn't that good and you consider it non-cannon.
If you do own the original it will harder to recommend this game. But know that it is like a new game with the same story and locations. The levels and movies are completely different. So if you don't mind playing through the same story and loved it the first time, this is a good buy. Note that you also get 3 extra levels in this edition as well as the ability to play as heaps of different characters, from good guys to bad guys and even C3PO!
On a final note it may be best to check that your system requirements meet the minimum requirements of the game, as well as downloading the patches from Aspyr's website. This may solve many problems with the game stated in reviews but I wouldn't know because I had no problems myself.