I've had a North Face 4 season bag for twenty years now and it still performs well. I used to use it on the Vallee Blanche and so on in -20C+ but now it only gets used in British winters and summers. I've only washed it 4 times, working on the premise that it's better to have a dirty warm bag than a clean cold one. I remember it cost over £100 then when North Face was specialist stuff not as trendy as it is now. Hope yours lasts as well.