I still think the body’s COG isn’t right…
Take another look at Richard Williams’ walk cycle above. Notice how the body’s angle remains the same throughout the cycle? Try eliminating the change in rotation here and maybe also push his body forward more.
When we walk we are essentially in a state of falling (our COG is too far forward) and we constantly catch ourselves by putting one foot in front of the other. I feel like this guy’s weight is too far back. Maybe it’s the rotation you have in his body that’s putting me off… He’s leaning back each time his front foot contacts and I’m not so sure it’s working.
Another thing that might look good is to increase the angle of the front foot just before it contacts the ground and/or removing any frames you have between the foot contacting with the toes up, and when the foot is flat on the ground. Basically, it will read better if it hits the ground in 1 frame.
I hope I’m helping and not confusing you!