UW is the gold standard for pure content. It helps you problem solve, but it is far more similar to the usmle style question than comlex (if that wasn't obvious already).
I got one of the comlex banks mostly to see if there were any random comlex-y questions to learn about and for the omm questions..they are pretty accurate for those.
After going through UWorld a couple times for the USMLE step II CK I breezed through comquest with relative ease. I had learned the material from the former, and there was hardly anything on there that hadn't been covered.....save omm of course. I think it's worth it just for those questions fwiw. Glad I bought it just for that reason.