Good stuff man! Can see some real improvement in your latest sigs actually, I've never really liked sigs with real people but your Jekyll one is compositionally very good. The second one I'm not as much a fan of but I'm not sure what it is about it that bugs me... Its still really good though, nice lighting, colours, text, and blending. Maybe it looks a little bit flat with the render just blending into the background? I'm not sure..