I bought the 87-93OCT/e30 combo tune back in July and I'm very happy I did.
@Clint Beastwood and his two cents is what led me to check Monster Tuned out.
To back up what
@pwnall1337 said with my own experience, I was throwing a code after I installed my short shifter (didn't seat the ECU to battery connection right) and the Monster Tune didn't adjust anything until after I fixed the issue and cleared the codes. Once I did that I noticed a night/day difference in power output after a few days of driving.
If you want some safety baked into your tune, I would recommend Monster.