Well I took the plunge and bought into the slim pack hype. I'm sure I'll need some extra foam for the battery strap to work but this seemed like a quick way to put the buggy on a diet and then put the extra weight where I want it we'll see what actually happens. I'm just happy they made a 3900mah this small
63 grams is the difference between my protek 6100mah pack and this one. The SMC was just there for size reference