Character design, seeking critique

Hello fine people of AWN!

I would like to share some character designs with you today. I am brand new to the forum, and what I look forward the most is to get some good solid critique.

I am doing this being inspired from the work of Tony Siruno, Ben Ballistreri and Gordon Hammond. But two eyes are often not enough to push a piece, so I am open to any suggestions, specially concerning shape choice  and technical flaws, such as tangents.

These pieces are personal works, not for any project in particular, but I am in the habit of treating them like production sheets, minus the turn around in these cases.