I chose the FL 20* with it being a good 3-season & the length covers my whole body.
If my back and/or my feet get cold, I'll be freezing the whole time camping.
I'm just starting out & I have just ordered the 20*top/20*under quilts.
For my birthday this coming year I'm buying myself the Clark tx-250 hammock. So by spring I'll be ready to go...toasty warm. In Minnesota you never know what temp. mother nature has in store for you.
I'm at that age now where comfort over wt. is more important. (within reason)