Your rendering is kick ass, it´s very exact and precisely, but your linework is a bit boring in my opinion. It´s like you are doing the same thing with rendering and drawing lines, you do it very exactly.
I´m far away from being a line expert, but I guess your drawings, especially your gesture studies, would be way more dynamic if you would make your lines more intuitively and with some more variation.
Maybe you want to try that!
Good luck and keep up the good work!