technically, they are the same size, but since they are way more square they dont fit some of my chassis'.
this is a prime example of what i mean:

with the maxamps pack, its just too square to fit down into the rpm chassis. also, the lead wires under the shrinkwrap add a little more length than what the hardcase's length seems to be since the hardcase leads come out the top. that maxamps pack comes to exactly 140mm with the extra wire bulk under the shrinkwrap.
and with the hardcase lipos, they look like they are intentionally curved around the edges to emulate a stick pack. i can see how this could work if the cells were placed in the middle of the case. can any of you guys confirm for me before i buy one and find out the hard way?