I have a 20 Phoenix and 20 Burrow on order figuring I can use them from 20 up to about 60. These will be my first quilts. Living in the South, for warmer temperatures, I'll use my 45 sleeping bag as a quilt with the 20 Phoenix or if temperatures are going to be warmer at night, I will try my SeaToSummit Reactor Thermolite Liner as a TQ with the 20 Phoenix and see how that plays. I have a funny feeling that I will eventually wind up with a 40 TQ as my 45 sleeping bag ways a projected (as I don't have my TQ or UQ yet) 16 ounces more than the combined weight of the 20 Phoenix and 20 Burrow