If we are talking about climbers then a Cougar claw beats the hell out of a Summit and API.
http://www.cougarclawusa.com/treestands.htm
They're 100% made in the USA, rock solid, have the ability to safely level the treestand while climbing, they have a built in foot rest, the cable system is one of the easiest and safest to use, etc... etc...
I wouldn't sit in an Ol'man if you gave it to me. IMO these are some of the most unsafe climbing stands on the market. I can't believe that the TMA would approve these stands.
If we are talking about ladder stands or lock ons then Millennium wins in comfort and build quality hands down.