Schomburg is one of my favorite artists as well based mainly on his work for Timely. Some of his later MM covers look a little too much like each other, but each one is very good taken individually. In general, I tend to prefer his earlier Timely covers, but there are some later ones that I like quite a bit, like MM46. (I can forgive him for the Young Allies run.)
When it comes to his work on Wonder and his work on the various Standard/Better/Nedor titles, though, I'm not as impressed. With the post WWII covers in particular, it seems like he was "mailing it in" for whatever reason (maybe those commissions paid less or maybe the editors weren't as demanding . . . who knows). His airbrush covers are starting to grow on me, but the characters look a bit stiff at times.