Thermolite Liners

Anyone tried any of the Thermolite liners by Sea to Summit?
Thinking it might be a good way to make my 3 season sleeping bag into a 4 season bag.
Thoughts?

Yes, I have the reactor one. As well as adding warmth it keeps your bag clean and if it's really hot you can have a nap in it while being safe from sandflys. In a pinch you could use it to keep fly's off your meat. Worth buying I think.

I have the same one and like it.

Sounds good, they long enough?

Yeah, plenty of length. They are a great product.
I've just used one inside my 400 grm bag on the Kaweka tops in a tent. It got a bit cold and wet, and I was damp when I hopped into my bag one night.
Was warm enough for the night.

Mine is long enough and I am quite a tall bugger. Check the exact specs on the web site though as there is a compact one thats shorter.

Used to have the reactor and used it inside a dangerously over-rated - 18 bag (0 degrees would have been more accurate) and was toasty well above the snow line with just a thermal mat and bivvy bag. Would have been a cold couple of nights without it. I was looking at getting their next model up, which is supposed to be even warmer.