There is quite a difference. With an ordinary neck sizing die the neck is forced into a space which slightly undersizes the neck, then the inside of the neck is sized correctly as the expander ball is pulled out of the case, some lube should be used inside and outside. Obviously the case body and shoulder are not touched. With a collet type die the neck is squeezed around a rod which resizes the inside of the case neck, the collet has 4 spring loaded sections which are squeezed by a cone which sits above it. As the press lever is lifted the pressure comes off the case and the brass 'relaxes' enough to withdraw without any effort. No lube is needed in these dies. I hope that makes sense.
I use almost exclusively Lee collet dies, mainly because I don't like crap all over my hands. I do think that I get more split necks when using these,especially with older cases. I have never mastered the art of annealing brass.