I just finished the opening level. Normally, it doesn't take quite so long, but I had a lot of false starts. In the end, I went with the Jedi Consular, because I like using the Force. The system for switching between powers isn't the best, but there's something fun about tossing enemies around, freezing them in place, and blasting them with lightning (I've not yet committed myself to the light side of the Force, but it seems likely that I will).
Overall, Peragus is an . . . interesting way to open the game. The first time you play through, it's incredibly creepy, with a deepening mystery and a gradual reveal about who you are and how you came to be in this place. It's an effective introduction to Knights of the Old Republic II's dark and pensive take on the Star Wars setting.
However, this is a game that is clearly meant to be played not just once, but multiple times, and while Peragus is useful for getting you into the mood of the game, it's not exactly a versatile or dynamic setting. Everything has to be done in a very particular order, and there's no opportunity to skip the things you don't like. Your character is plopped down into a situation and must deal with it no matter what. I think Peragus is a better story that the original KOTOR's Taris, but as a game, the latter's additional freedom and mobility make for greater replay value.
And as much as I like the opening story of Knights of the Old Republic II, even I have to admit that it's not really meaty enough for sustained and repeated interest. It turns out that you meat an extremely suspicious protocol droid which has been programmed to act as a bounty hunter, and most of the middle part of the Peragus mission is you realizing the droid is responsible for all these atrocities and slowly uncovering how it managed to pull them off. The way the droid casually and remorselessly slaughtered the miners and betrayed its own co-conspirators was nicely unsettling, but there isn't much there under the surface (though I do like the droid's characterization - it was so smugly evil that blowing it up was a genuine pleasure).
The last leg of the Peragus mission involves boarding a Republic ship called the Harbinger and learning more about the real main plot of the game. My character was apparently a rogue Jedi who served under Revan before she turned evil, and then went on some extended walkabout during that whole "Jedi Civil War" unpleasantness that was going on in the first game. As a result, he missed the purges that left the Jedi order nearly extinct. Now he's back and he's being hunted by the Sith, who want to kill all the remaining Jedi and extinguish their tradition permanently. Also Carth is still around and he's an Admiral now.
My actual goals, going forth from this point, are still a bit vague. The Peragus mining colony got blown up due to some careless blaster fire by the Sith, I have a mysterious psychic connection with Kreia, who seems desperate to be my mentor, and I picked up a scoundrel named Atton who is obviously more than he appears. I haven't yet stumbled onto any major plot threads, aside from the Sith assassins, but I'm sure the planet of Telos will be more forthcoming (though maybe not - for the life of me, I can't remember what the hell this game is about).