Not sure about what the pros are doing, I don't think that's remotely relevant for Joe-Average, but from a "normal" surfers point of view, having some volume up front makes paddling a lot easier on smooth water, although it can mean you end up "pushing" water if its a bit choppy.
Having the volume up-front means you can get your chest and head a little closer to the nose so it makes catching waves a good deal easier, which is ideal for small or weak waves. We're not talking like a fish or a longboard here, but a noticeable difference over a skinny-nosed shortboard.
The disadvantages are that it may turn a little slower (but only at the top end of the skill level so it makes naff all difference to me), and the fat nose can mean very steep drops are a bit sketchy - but that shouldn't be an issue on small Florida waves
