OoOoOo... he could be part ES! I'm not positive, but I think long hair is recessive, which could explain the smooth coat.

I always thought he was ACD x Lab. My friend has a Border Collie x ACD with the same ticking pattern, just with a few more black patches. His body type and ear-set seem to be right in between an ACD (stocky, prick-eared) and a Lab (lean, drop-eared).