UL Summer Bag+ Liner

I had one of those for a year before I returned it to REI to use the money towards something actually useful. It does add warmth, but then again ANY additional layer does. It certainly was not the claimed +25F; maybe 10 tops but probably only +5ish degrees. Difficult to know for sure because I didn't use it in the exact same conditions as when I went without it, but it just wasn't worth the weight and money. I will say my skepticism with the temperature claims began when I used at home on my bed; it wasn't warm enough by itself in a ~60F bedroom.

Personally, I think you're better off putting the money towards a down or synthetic jacket that will weigh the same or less and provide more insulation where it counts, as well as being useful outside of your sleeping bag. That's what I did.

Jeff

No magic, no free lunch. Adding that liner won't turn your 45F bag into a 25F bag. Look at the specs for other bags– a Lamina 20 is more like 3lbs. That liner is like a super light fleece and the 20F gain is extremely optimistic, if not outright deceptive. You need loft for warmth, and 1/16"-1/8" of polyester just isn't going to deliver that.

I like a 32F bag for summer use and a 20F for shoulder seasons. If I had to choose one, I would get the 20F.

if your going to add a liner, add it for a little more comfort and to keep your bag clean, not for warmth. i use a silk liner because its light, i think it cuts down on drafts, and it keeps my bag cleaner so i don't have to wash it often, about once a year for the bag and i just wash the liner after every trip.

if you really want to add warmth to a bag, use a warmer pad. i use a neoair allseason now, and with my golite 40 degree bag and a silk liner, im comfy down to 30 degrees, and would be chilled but easily survivable down to 20 degrees. If i used something like a exped downmat UL7, thermarest XTherm, or a kookabay pad with an R value over 5, it might help a little more.

if your wanting a do it all 3 season setup, get a 30 degree bag and a pad with a 4+ r-value. that'll keep you warm to 20 degrees and then you can just vent it at warmer temps.