Size of pots - capsicums etc

A guy down the pub advised me that "sweet" bell-peppers need pots rather larger than their "hot" chilli-pepper cousins. Is he right?

I tend to discount advice from "the guy down the pub" but this one does know more than I.

 

I grow sweet peppers in 9in pots.
Sometimes a bit bigger.
Chillies do tend to be smaller plants with less leaf, so can be grown in smaller pots.
Both need feeding and watering well in hot weather though.