looks pretty good, and either face looks like they'd work, just depending on what kinda of mood/emotion/intention you wanted to convey.
MA Arcs - #67636, #92202
deviantart page
Slag Heap: Why you hurt Guardian!? Guardian no hurt you!
Nice! I think the replacement face looks best 
yeah, i originally wanted a roar, but ended up with a "scared looking towards the heavens for answers" kind of face. Then I redrew it and managed to fix the angry.
Liberty
My 50s:
Hero: Armor Assassin (scrapper), Cross Dresser (scrapper), Surly Seaman (blaster), Defensive End (Tank), Rad Rhino (Cont)
Villain: Beast Infection (Corr), Sweet Zombie Jesus (MM), Milk Weasel (Stalker), Orgullo (MM), Agent Eris (Crab)
Sketched this last night. Got to the scanner and didn't like the face so I sketched a new face real quick for replacing it when i start the digital. Gonna begin coloring tonight. I present to you, Rad Rhino
Liberty
My 50s:
Hero: Armor Assassin (scrapper), Cross Dresser (scrapper), Surly Seaman (blaster), Defensive End (Tank), Rad Rhino (Cont)
Villain: Beast Infection (Corr), Sweet Zombie Jesus (MM), Milk Weasel (Stalker), Orgullo (MM), Agent Eris (Crab)