the main difference is that the bullet packs spread the weight more evenly front to back...while the saddle pack will distribute the weight more specifically in the rear.
oh, the micro rs4. I ordered 6 KAN cells, from blind. I was thinking of ordering from you cuz they are cheaper and new, but I really need a Titanium Hinge Pin set from blind for my mini-t, (thank you blind).
btw, I run the ARM pan chassy so I have some extra room