What makes these hammocks different is the way the ends are cut, the shape of the hammock body itself and the manner in which the hammock hangs. The cut of the fabric creates "pockets" at the head and foot of the hammock. These "pockets" allow the user to lay flat. If you notice the photos I posted, you can see this feature if you look at the bottom of each hammock. The user lays on a diagonal, as you should do in any hammock, and with the added material of each pocket the over all hammock length can now be shorter and still have plenty of room.
The bed liner is 80 inches from head to toe. I am 6'2" @ 235lbs and have plenty of room.
I don't know many people who are 8 feet tall and I never see many 7+ foot basket ball players out on the trail or while sea kayaking. If I do and they need a hammock, I will design one to accommodate their needs.
Here is a video that shows the inside of one of the hammocks.