Have used with ground frost (on Therm-a-rest mat in tent) and was comfortable, even a little too warm. The bag appears quite well made and of a decent quality.
I brought in a bit of a hurry without really knowing much about sleeping bags and now I find it's unsuitable for lightweight hiking as it's big and heavy compared to other modern bags. On my scales the long version (195cm) is just over 1.7 kg and it doesn't compress very well. It's very difficult to get it back in to its own bag so I had to buy another, but rolled up the smallest I can get it is 35 cm x 20-25 cm at best; normally i just roll it up and its between 40-50 cm which is big and I have to put it on the outside of my rucksack.
Given that this is rated at -1c comfort I don't think the size and weight are very good considering a down bag of that size and weight would go down to -15 comfort. However it is relatively cheap at £80 now and the chest area is generous and more roomier than Marmot wave bags I've tried in comparison. It's ok if weight and size aren't a problem for you, but I wouldn't buy it again.
Price Paid: £110
Had this bag for about 10 years, roomiest bag I have. It's not great on the compression or weight fronts, but definitely a comfortable warm bag.
It's great when weight isn't too much of a concern eg car or kayak camping. I have used this in the spring in the Lake District with a fleece liner and been plenty warm a few degrees below freezing.
I've not noticed any degradation of the bag (apart from the writing on the bag wearing off), but have always used with a liner, hence low dirt and wash cycles.
If I'm just heading off camping and won't have to lug the thing too far, this is normally the bag that I grab from the gear room.
Price Paid: Bought in 2001 (retail)
Just retired the thing in favour of a down bag.
Ideal for backpacking in colder climates, super light. Mine did me well in the Canadian spring & kept me alive in -20 degrees C. Despite this, it has a couple of problems:
1. Even the shortest bag was too spacious for someone who is 5'7"
2. After about 3 years of use, the filling suddenly failed to keep me warm... a couple of miserable days in the Cairngorms this summer prompted me to buy a new bag.
Temperature Rating: -14 degrees C
Price Paid: £100
The best £100 spent on a bag! very wide and long, supremely comfortable and designed to fit. little degredation after washing, conservative temperature rating.
Buy one now, forget Polarguard - it doesn't last at all.
Fill: MTI Loft
Temperature Rating: -5c
Price Paid: £100