Does anyone use these?
http://www.strombergschickens.com/prod_detail_list/transportation-coops
I normally just use dog crates.
Those will result in a LOT of broken feathers too (especially wing or tail feathers that stick through the gaps, bird moves, broken feather). Dog Crates or handmade wood crates work really well. Used to use these when we raised a yearly batch of CornishX for meat and they worked great for transporting those to slaughterhouse.