The first two are extremely well done, you have an eye for turning basic lines into a smooth, flowing form. I don't know if compilation pieces are something you are fond of, but I think the images are juxtaposed very intelligently and the space is effectively utilized. You mentioned the feet on the first one don't look quite right, I would recommend looking at some reference pictures to get an idea for how calves and heels are structured. I think most of the issues with the foot on the left could be resolved by eliminating that dip where the top of the foot meets the leg, and expanding the left boundary of the boot's sole to make it look more like it is facing the viewer. As for the one on the right, you have to remember that there is a foot in front of that heel, try using some of that excellent form to bring out the sides of the boot and foot. (Feet are a common point of contention for me, too. It takes some practice).
As for your Gideon concepts, I really like the head shot, but remember most necks (especially on burlier subjects) are thick enough to terminate at or near the ear lobes (actually looking at it again I can see you were drawing a free-floating head, but I left this comment in for general advice). On the full body shot, Gideon is pretty well constructed with the exception of the shoulders and arm musculature. I would suggest smoothing the upper boundaries of the shoulders to meet the collarbone in a more natural fashion. The bicep could also use a redo, try making the upper part of it meet the shoulder more naturally, and as you work your way down the arm make it a little thinner as you go.
Zylos (as with your other full-bodies) is very well constructed. The face is so-so, a little flat but I can see you have greatly improved over the past year.
Hope this helped, and keep up the good work!