LOL, guess this is a matter of who is on the receiving end of inconsiderate people more than what you are using.
We love umbrellas (tiny fold ups easy to carry). BUT, we are 'very' conscious of what/who is around us and don't go out in 'driving' rain - we'd rather wait.
We have been soaked by people in ponchos that could care less if they brush up against you in the parks, also inside when they decide to leave them on. Have been very dry on a bus, and families get on, leave their ponchos on, and sit beside you - yuck!
So, IMO, it's not what you use to keep yourself dry, it's how considerate you are around others.
Personally, we can't stand the humid feeling of being inside a poncho (tried them), but I think it's whatever makes people the most comfortable and happy.
Very true and good point. I personally don't like umbrellas and prefer a poncho. Others are different. OP - go with works best for you.