wings of angels is mandatory. if you have enough density just dont press it (or when your pony is not doing enough dps to oneshot everything because you don't have the right gear/paragon/thorns) . if you have to cover long distances it is a very pleasant speed boost.
your clear time is considerably better with speed buffs. there is no "too fast". there is only non optimized gear/stats.
p.s. don't use speed pylons, they will completely wreck your pony