Hello, I stumbled across your review while doing some research and I had a couple of questions for you. First, let me say it was a great review. I was wondering if you knew what size the serape could be compressed to if I wanted to stuff into a sack or bag? Also, you said the serape didn't zip up all the way when used as a sleeping bag. Do you think it would be possible to attach another zipper (or maybe even velcro) so the serape would close all the way?
1) size the serape could be compressed to if I wanted to stuff into a sack or bag?
I'd say slightly smaller than a 2 liter soda bottle. If forced to be more specific I'd guess about 1.75 liter but lets say two to have some safe room.
2) Do you think it would be possible to attach another zipper (or maybe even velcro) so the serape would close all the way?
The zipper arrangement on the Serapa for the 'sleeping bag mode' comes about 40% of the way up the bag. For me it comes to about crotch level. It is a bit unorthodox but they use the one zipper for this and the 'greatcoat' mode so I am sure there is a balancing act there. The zipped foot box keeps you in the sleeping bag and the dimensions are generous enough to avoid the 'on the edge of the blanket so there is a gap' affect. I just sort of wrapped up in the top part like a burrito. For me it worked fine. The arrangement wouldn't work for an expedition weight bag designed for -20 temps but given that it is a fairly lightweight sleeping bag designed for light 3 season (probably 2.5 season to clip off the very early spring and latest part of fall) it worked fine.
Coming back to the question, while I do not see the need, if you are handy with a sewing machine one could certainly add a zipper. It would have to be one of the ones that come apart like on the front of a coat. Also that would mean there was a zipper on all but one side which could make for less than optimally comfortable blanket use. A couple pieces of velcro could have basically the same effect and be easier to put on. Either way you could certainly do this if you want. I'd recommend trying it as is for awhile before adding anything, those guys really test their products and you might find that while unorthodox it works for the intended use.
Hope that answers your questions