I have found camping bags a little too small and restrictive. Another angle is that having a crash zipp is not a reqirement of a camping bag. My previous bag was a camping bag and was rated down to -15. I replaced this with a Sundridge heat control bag, and to be honest there is no comparison. The Sundrige bag is huge with loads of room to move about in, and it is just so warm and toasty in comparison. I recomended this bag to my mate, and both of us now consider these bags to be one of the best carp fishing purchases we have ever made. This is quite a claim when you consider I have been fishing for carp 19 years.