First off, I'd like to say that SR is the only original content mod which fits in with vanilla content perfectly, that I can think of. And some of it is even better than Bio's actual work! I had played the original BoS, so I'd been keeping an eye on this baby. I reinstalled KotOR just to play it.
Technically, the mod is a marvel. The amount of gorgeous new models and skins, scripting and maps is awesome, and the recycled maps were pretty well done too. Excellent VO overall, but Kobayashi's looks like it was done by a pro. He's my new fave NPC.
From a writing standpoint, the mod manages to consistently maintain an atmosphere of suspense and dread during the Korriban phases, and the change of pace during the flashback sequences is very, very nice. The mod seems to integrate seamlessly into the continuity, too. That is is, by itself, worthy of praise, considering the huge mess the SW canon is.
Now, on to the criticism.
My only beef with the mod is NPC (and, to a lesser extent, some battles) design. I wish mods weren't designed assuming that the player is a compulsive grinding powermonger... because that means those of us who aren't are in for a rough ride. I don't have a problem with difficult games, but cheap shortcuts to increase that difficulty are no fun, and it gets worse when stuff isn't even consistent in-game. For instance:
I can understand that Force choking the incorporeal form of Akirakon Sin is a pretty stupid thing to try, so he's given insane FORT saves. Okay, that makes sense. But why does Mandalore the Ultimate have +13/+10/+13 on top of his standard class saves and on top of the JEDI SENTINEL state immunity effects? If each +1 is an additional 5% chance to save, +13 is +65% (!), again, unexplained, unwarranted, and on top of already unfair immunities... making using the Force against him a waste of time. Unless, that is, you somehow manage to get your WIS to ~40, to offset his bonuses. For comparison, vanilla Malak has similar bonuses to his saves... but he's supposed to be drawing on the power of an ancient Dark Side artifact. Speaking of which, it's odd to find that the Mandalorian Wars version of Malak is murder incarnate... even when compared to his Dark Lord of the Sith self.
All in all, I think perspective was lost when building NPC character sheets, what with everyone and their dog being level 20 behemoths of destruction boasting ridiculous saves, defense scores, FP totals, etc. This is still supposed to be a d20-based system, isn't it? Han Solo, Obi-Wan, Vader and other "big" characters aren't level 20 characters. Artificially raising the power level of, well, pretty much everyone to "provide a challenge" results in a state of affairs where power means nothing and tactics are pretty much reduced to spamming stims and life support packs... of which there's an overabundance, which in turn nullifies the intended "challenge"! I don't know about you guys, but I don't remember Obi-Wan and Anakin making pauses in their duel to dope up, and Anakin didn't lose because he ran out of hyper-adrenal alacrity. Pretty atmosphere-breaking, if you ask me.
Regardless, I've enjoyed playing through the mod immensely. This is without a doubt top notch work, and a must-have KotOR add-on.