I have 3 round burst with a burst wizard in my Sten. There are times you might use full auto but several 3 round bursts do the same thing but with more control.
I tend to triple tap on semi auto anyway with my M4, and that's easy enough to do without the gun doing it for you. Three rounds is good for suppressing and for aimed shots as well. Full auto just rips through your ammo too fast.
