That chugging you experienced was because of the AI going into "search mode", it caused framerate loss of up to 99%. I ran quite a thread about that issue on the official website for awhile, developers said they were looking into it, promised to patch it yadda yadda, and in the end they never did anything about it. Bastards.
In any case, you can probably fix it by switching Vsync back on, or by lowering your soundcard acceleration (in DirectX).
Switching Vsync back on fixed the issue for me, I tested it well over a hundred times on the India level, no Vsync = 0.2fps, Vsync = 80fps.
Ofcourse, since patch 1.02, cutscenes no longer do anything, they just sit there.
Definitely pissed off with the way they fuxxored that game, both in release and with their patches (fix one thing, break another, ignore yet another).
Other than that, it was a great game.
As for the Lithtech getting a new name, it was to be expected. The whole Lithtech gig was still being run by guys from within Monolith, and presumably doing both just got a little too hectic. I'd imagine Monolith keeps making shooters, and the whateverthey'recalled guys now focus strictly on the design, licensing and support of the engine.