I have kangaroo collars, for Emma. They're too rough, for Ena, even broken in. Neither wears collars all the time, but I've been pretty happy with them. Emma also enjoys collar grabs and rough play, and they're fine, with that. The leather seems pretty strong, and is just getting nicer with age.
Of course, that is with the disclaimer that mine don't wear collars unless they're out of the house, and they don't wear the same ones all the time, so.... meh. Might not be that helpful, LOL. Emma's collars are built like these
http://handcraftcollars.com/popup_image.php/pID/28?osCsid=df6232e4dfdf2a16231c6df72984f8f9
With a snap on one end, a ring on the other, and a floating ring. It was done for a better fit. She has a big, ol, doggy head.