I frequently use a heavily weighted Caddis Pupa pattern as a point fly (kind of a Czech Nymphing rigging). The question of whether to tie a dubbed abdomen or a smooth abdomen has never been settled for me. I tie both and frankly have success with both styles. The scraggly, dubbed body has trailing fibers that suggest life and attracts, I think, by creating a shroud of bubbles about the fly’s body.
The smooth bodied Pupa pattern (latex wrapped to create smooth, segmented abdomen) keeps that wet, translucent look to the fly. The smooth body’s complimented with the gently dubbed thorax, which gives a hint of movement.
Which is better? Tier’s discretion and fish’s selection. Try them both. Match the fly’s weight to the water’s depth and speed (streams).