Keep in mind I think its way great the way it is.

This part seems nitpicky to me but you asked for coments.. and this is the only thing that I can see so far so it much be pretty damn good.

Ok I think I see it better, it toke me a little to finger it out. LOL about 12 views. I'm no animation expert. Also keep in mind I might be interpreting things wrong because I don't know much of anything about the story line. (don't want to yet either. LOL) What I was seeing about him being stiff, was he's not really stiff.. it just looks like he's walking like he's stuck up, or he's about to get in to trouble. That all looks good.. but what I was seeing really was his arms,, they look like they swing to much for what the rest of his body is trying to say.. There looking very relaxed and the rest looks tense.. but a good tense because there is some reason. Ether he's walking with a purpose or he's watchful because he's about to get in trouble. or something.. LOL that all looks good, just seams the arms are not conveying the same thing as the rest.

is that a bit better ?

btw after watching it so many times I'm rather amazed at it really.. the body, legs, head all seem to be like perfect.. to me at least. and its funny just watching the couple of seconds of it.