Price/performance/weight. The cottage industry TQ's are the best.
I've messed around with both the TQ's & bags. I'm down to the fact that the only bag that will work for what I need comes from Western Mountaineering (Latin for "bring your wallet"). I can buy 2 TQ's rated at 0* and have change left over for a nice tarp for the cost of one.
Western is top quality gear and their temp ratings are accurate. So are the cottage quilts.
Love is blind. Marriage is an eye opener.