I'm not sure anyone here is going to be able to answer your question, as CO does not have lie-flat seats on any of their aircraft, at least according to the standard definition of lie-flat. Yet you claim to have flown in them. So, not quite sure whether you'd consider the BE seats on DL's 757 lie-flat or not in your definition. They're nicer than normal F, though.

ETA: I see CO does market their 777 BF seat as 'almost flat,' my mistake. Regardless, the 777 seats certainly have more recline than the 767 or 757 seats, which are comparable to DL's BE seats.