I used bag liners for years in rifle season conditions. I have a new 0 degree that keeps me toasty but a bag liner plus a decent bag is nice in some circumstances.
I still have my OG woobie and my "Canadian woobie" that the Army started issuing in 2008 prior to going overseas. It's a zippered woobie with a poncho head hole. My kids always steal it from me. Hands down the best sleeps I've had were in that thing.
Something about curling up in my woobie brings back memories of quiet nighttime OP shifts in Panjwai. The cold mountain wind blowing through as the sun pierces the horizon and the valley starts waking up.
Sorry Im late to the game, I just saw this thread. I have a reactor, bought it with my Western Mountaineering 10 degree bag. I hate being cold. Havent used either but as I was reading this thread I was wondering why the sleeping bag manufacturers don't line their bags with fleece?? Hell, I paid $1,500 for that bag. Do you know hard it is to find a rectangular shaped bag that has a low temp rating?? It's an extremely well made bag. I wanted to buy one in 2022 and they cancelled me on my order. Matsrials shortages back then. So in 2024, when I saw them available I scooped one up. In 2022 I ended up buying one of their heavier down queen Quilts and having my boat apholstery guys folding it in half and sewing in a double-sided zipper into the bottom and side. Its not as heavy as the bag but I can use it as an exterior bag to double up, or just use it as a lighter bag. I can put the 10 degree WM bag in it to get say a -50 or -40 bag.