The biggest problem with the score, at the time, IMHO, was that it was optional: you got it if you had the CD in when you played. I rarely bothered to dig out the CD, so most of the time I played Quake I didn't have the musical accompaniment, and really, it makes a huge difference to the atmosphere.

TR also did the sound effects for Quake, which I think are a more mixed affair. Some individual sounds, in isolation, are great (the invincibility power-up being one that pops out for me) but they didn't sound all that cohesive together. Certainly not as much as Doom's sound effects.