In case anybody ends up on this thread with the same question, I ended up pulling the trigger on a HUUB Archon for $200. It has a 3:4 buoyancy profile, with thinner 1.5mm on shoulders and armpits. It looked like good bang for the buck, flexible shoulders, with a bit more thickness in the bottom, but without being as extreme as the 3:5s. Looks like a good compromise between the 3:5s and the 4:4s.
Looking forward to try it out.