I'm sure you'll get alot of different opinions....but I'm partial to shavings. The pooh seems to "clump" in the shavings instead of getting embedded in the feet feathers, and even if it does, it's easier to pull out.
Also, I haven't noticed any foot feather breakage with the shavings; which is an added bonus.
Plus, my birds are still able to take "dust bathes" in the shavings.
In small areas with the shavings, I can use a kitty litter scoop to do a daily clean up
I am by no means a expert, but I think it depends, are you conditioning them for show? If so most people keep them off the ground on thick shavings (4-6 inches). If they are just pets, I dont think foot feathering is that important. I think you can go to www.silkiesbygeorge.com and look under coop, there are some pens on there. Hope it helps.