Alternate Arm Study
I mentioned in the description of my very first MCS-m build that I wasn't thrilled with the arms, and while I've warmed to them a bit, I still feel like they are easily the weakest part of the design.
Mostly these are variations on Vitor Faria's excellent Lockon arms, though you may recognize appendage's used on Markwisski's Deadlock C, and also my own Dweor. I think my favorite of the bunch is probably the one on the far right (seen in action on my Lockon Kai "Stars and Bars"). It combines the Lockon shoulder with a more articulated elbow/wrist joint and doesn't look excessively long on an MCS-m. The Deadlock C arm is close second, but only falls short for being a bit on the bulky side (not ALWAYS problem, mind you!)