[jesnell]

SBCL set out to make a version of CMUCL that was easier to build and maintain. I'm pretty sure that was delivered.

But of course that's not of much interest to the average user. I think SBCL is in general faster, is developed more actively, has more features that are relevant in the modern world (eg. lose a Motif interface, gain native threads), and currently runs on more platforms than CMUCL does.

My impression is that most people using CMUCL are ones who started using it 10 years ago and are comfortable with it, new users would tend to go with SBCL. But I'm biased, so it's quite possible that there are real and substantial reasons to prefer CMUCL.