I'd like to point out that personally it's not about which UI I like better: I'll go with the solution which offers me to never need to see their UI again after initial setup.

I know Nexus for example can be controlled automatically during the release process via REST calls, so that would work for either OSSRH and JBoss Nexus. I'm quite sure that BinTray (Artifactory) have some options for this as well.

Having removed UI from the equation, +1 to pick something reliable (so that indeed I don't have to go an face the UI - or worse even a ticket system). Fast to synch is nice as well.