The genuine US cots are good but there is a technique to getting the end bars on, you basically need a lever. Carp fishing beds are a superb option, though bigger, bulkier, heavier and more expensive. Cant be beaten for comfort though. I use a campmor army officers bed, it was hellishly expensive for what it is, but it's superb. It packs to a similar size to a US army cot, but is welded steel construction so is about 3x heavier - it is also sprung - that's ace.
Aside from being steel, properly sprung and better balanced than the US cot, one of the main advantages of this cot is it's height. The higher you are inside a tipi or belltent, the less room you have. The US cots sit quite high off the ground, which means you have to bring them in from the sides of the tent to get the hight you need. I found it dramatically reduced the floor space of the tent. The Campmor though, is about 2/3 the height of the US cot, which makes a fair bit of difference inside a tent. That said, I cant recommend one on the basis of cost, they are just too expensive for what they are. If I was buying again, I think I would go for a carefully selected carp fishermans bed. You have to be careful not to go daft with the fishing stuff though, some of it is stupidly massive.
On top of the campmor officers cot I use a campmor roll up mattress....
Super soft and super warm, it's 2 1/2 inch thick foam covered in cotton. Light but very bulky - it would completely fill a large bergen on it's own. Works perfectly with the officers bed though.
