I have been trying for quite a while to get a "tougher" sound using the J&BB kit in big band scores but it always sounds a bit too polite for rip roaring stuff. Great for small groups, ballads etc but seems to be lacking something in the full on things, particularly the fills. I think that it may be due to the snare sample having the snare on, whereas I seem to remember my drummer friends always had the snare off for a tighter, crisper sound. Does this make sense?
Snare drums can vary quite a bit in sound depending on the brand, size and tuning. Snares off will cause the drum to sound more like a tom. So your friends probably had their drums tuned a little higher.
I find that one drum library can't do it all. So I have a few companies libraries and change my kit depending on the style of music I'm doing. I may use the same kit except change the snare if I want the higher poppier sound.