Robeez made Jett's feet and ankles look terrible. I bought them for him, let him ride in the sling all around the mall with his new sandals on and then promptly returned them. Even though they were on the big side (for this summer) they were STILL too tight on his ankles. I didn't even think his ankles were THAT chubby.
My daughter's got chubster feet and the Robeez knockoffs at Target suit her well. You could try a pair on him (they are hung up in bags but you wouldn't have to rip the bag open, there's a snap, I believe.)