Used my Warbonet travel sock this weekend for the first time with my blackbird. Temps were -5c (23f) with 100% humidity (were calling for freezing rain but I didn't get any where I was). Had my 3 season burrow and incubator and I stayed toasty warm. I did get a fair bit of condensation in the sock but it didn't really cause any problems except when it camme time to pack up. Lots of ice crystals and frost. I just threw the sock into the truck and not into my pack.
Living is south Ga Ive found myself very comfortable in my HG 3/4. Ive had it down to the 30s and up to the low 70s. Works great from all the ranges we see.
I've been testing a modified Garlington insulator--one without the trash bag (in essence, my poncho suspended under the hammock with a space blanket crumpled up in it to block air movement)--above 50*, and it's worked well for me so far. I've used it down as low as 55* (hoping to see lower temps this coming week) and been comfortable. The total weight penalty for that (since I carry the poncho anyway) is approximately 4 oz. I wouldn't trust it lower than about 50*, though, I don't think.
I do get a little condensation occasionally, especially if I don't wear a shirt to bed. However, I'm also a sweaty dude most of the time.
Also note that I'm also a very warm sleeper compared to most; bag ratings for me are 5* to 10* F too conservative with most bags (i.e.: I can take a 40* bag to 35* or even 30* comfortably).
If you want a short overview, I did a bit on it in my trip report video below (it shows up at about 8:35):
"Just prepare what you can and enjoy the rest."