Geez, I am tired! I kept looking at the feet thinking there was something really odd about them, and didn't even realize that the "oddness" was that they were black instead of white!!! I have a better excuse for not noticing the feathers -- they're slightly out of focus and blend in with the background.
Hopefully I can now contribute something intelligent -- I don't know about roosters specifically, but Silkie mix hens are often much larger than pure Silkies, so I would imagine the roosters would be also. Silkie mix hens are highly desirable and sometimes specifically bred for people who want them for natural brooding. They retain many of the physical features of the Silkie, such as dark skin, five toes, feathered feet, etc, and still have the brooding instinct of a silkie, but don't have the silkie feathers (which many people don't like), and can cover as many eggs as a large fowl. I knew someone that custom bred them. She had several different breeds of hens, and several Silkie roosters. She didn't put the rooster in the breeding pens until someone requested a particular cross, then he was put in for one week, the eggs were collected for up to three weeks, and sent to the person requesting the particular cross once weekly or twice weekly until the customer had as many eggs as they wanted. The hens were not bred again for at least 6 weeks after the last breeding, just to be sure all the previous sperm had cleared, in case she got another special order. She didn't have many customers, but it was a niche business that worked out great for her, since all her birds were pets that she was going to be keeping anyway, and this just required a little custom management. She was quite elderly and has since passed away, but those Silkie mixes were the best broodies ever, and much larger than purebred Silkies.