I've got a JRB No Sniveler and recently got a Nano7 hammock for Christmas. I love the Nano7 and can get a good diagonal lay in it.
However, I seem to have trouble getting my underquilt to fit snug. Previosuly I used it on an ENO DoubleNest and it fit great (I know, going from real big to a small hammock). I tried shortening up the shock cord on each end to tie the underquilt with more tension. It looked like a good fit, but sleeping in 50 degree weather I would get cold spots every time the wind blew.
It looked a little like the edges of the underquilt were loose on the sides which was letting the breeze catch as I lay diagonal. Both ends were cinched pretty tight. I plan to try shortening the shock cord ties even more to get more tension, but don't want it so tight that I loose loft underneath.
Any tips or suggestions from those that use an underquilt with a Nano7? Perhaps I just need more fiddling having only slept all night in it once.