I looked at the Slumberjacks at a local shop today and will be showing them to the wife later.
I take it by your statement that they come in LH and RH zips? The shop only had RH zips.
How would you rate their warth accuracy? They had 0*,-20* and -30* bags, but nothing in the 20-30* range.
No, on the rectangular bags you just unzip one all the way, lay it out flat, unzip the second, lay it upside down on top, then zip the two together.
On mummy bags you have to have LH and RH bags because you lay them side-by-side.
We've used ours a few times, but always well below the rating, so I can't really rate them on rating accuracy.