OM, do you have any problems with the lower part of your legs "hanging in the air" due to the thickness of the 3/4 Insulmat? I haven't yet tried it, but thought it might be a potential problem for me. I suppose I can put my empty pack under there to take up some of the difference in height.

I may have been wrong about the weight; 17 oz sounds more like it (I think I saw 15 somewhere on the web, but that's less than 3/4 the weight of the full-length one). I'm looking forward to using it!