I like the original, though I see some benefits of off the MK 2.
I dislike the 4 arm setup personally, Can't see how we could control the suit if our arms are outside and if it would force mirroring.. I'm not too big on the idea personally. Seen it, it's kinky but not my flavor.
I do think people should understand that this is a standard (Medium) frame of the game, which means it shouldn't be getting hit that much. I feel it might be too on the light side atm, and a bit more focus towards that middle ground would make it perfect imho.
Everything else is fine really. Should be really be looking like a drill robot? It's supposed to be EXTREMELY resilient to damage, because of it's size, it will get hit. We're not meant to be as bulky, at least not on the Standard (Medium) frame.. On the heavy one I could see this (still not a fan of 4 hands however..) but then again I would say Heavy frame should be bigger than medium one anyway.
All in all, this is my opinion, everyone has their own. I think you're doing a great job. Don't start doubting yourself. You had an idea, let's see it in action, opinions based on drawings and pictures are tough. We're judging aesthetics and people are throwing in functionality without the feeling of a frame. You'll have a mixed batch of feedback because of how people may preview an image, how their eyes judge.