I haven't been an engineer for a good many years, but I was back in the eighties. Condensers are great for bass - especially on lower-powered amps (read:B-15s) and upright basses. For larger, more powerful amps I trust the durability - and lower sensitivity - of dynamic mics for best results.
Large diaphragm mics sound great on B-15s and I had good results with large and small diaphragm mics for upright in various combinations. A large diaphragm condenser on the treble-side f-hole in conjunction with a small capsule like a 451 pointed right at the bridge from straight on is a cool combination. Play with distances until the phases line up.
That's not to say that you can't get good recordings of upright using an RE-20, SM7 or other large dynamic, but you'll have a little less "air", which is not often what you're looking for when you record an upright. SM-81s, I found, were sort of a middle ground: a condenser that sounded just a little like a dynamic. A great all-around mic, actually.