I think it depends in part on how aggressive you ride. I used to be aggressive and wished I had discs because in an "oh no!!" stop they will work better. They also wont fade on long hills. Now I am old and give myself a lot more breaking distance and think ahead further and never really think about it.
So if you want to be an aggressive urban cyclist in the rain barreling down hills and screaming to a stop, get discs. If you want to ride like an old fart like me rims are fine.
signed- a former aggressive urban cyclist who is now and old fart.