Thanks for the approval! ahah, I can't wait to get into color, but I'm liking to share some WIPS.
About the concept... to be honest, I restarted around 3 or 4 times, I just wasn't getting the sculpt right, the process was messy and bruteforced, so I reset the sculpt until I got it to a stage that it sucked less.
All the time while working I was cursing myself for not doing this in Maya, which is the software I'm more comfortable on, but I did it, powered through and used only Zbrush for this... the reason being that process is more important than outcome, (for a creative anyway, not a client), if you rely on outcome, you already know where you'll get at, but if you focus on process, you may not know where it'll take you, but you know you want to be there!
Here's an arm.
It's also another part of the mech that I'm not shy to show, but it's still gonna get improved later on. There are somethings in it still bugging me.