Before the winter sales on steam, the only game from the dark forces series I had played was jedi outcast. I thought that game was the dog's bollocks until I got this. It wasn't better as such, but it added so much more, and if you have the money I whole-heartedly recommend that you get both and play them in order. Otherwise, I would recommend this because you get the dual sabers or saberstaff, and lots more lightsaber battling, although Jedi Outcast is more of a challenge.
I love this game, and have gotten so much fun out of it from my steam copy, but I have multiple friends who have bought it and not liked it. I would look at other reviews, and possible videos which show gameplay. A large part of this game, is liking RPGs where you contribute to a character over countless hours, by getting further in the world, getting better gear, and doing all of the things on offer. The gameplay is very varied in my opinion, as I like the genre, but if you don't it becomes monotonous, and it is essentially just grinding from start to finish for some people. Best played with friends, but by no means essential.