My "Prey" swimmer which is a surfster has a belly weight. I have tried other surfsters and did not like the wide roll they had. The weight cuts down the roll and adds a sexy wiggle action at least in my case......not traditional sure but I find the action alot more to my liking and the fish seem to agree.
I fish mine in all conditions.....day, night, calm water or rough, fish it in the Canal with great success! Stormy rough water it seems to excell in.....nightime it crushes!