I recently bought one of these for Della for canoeing (weight saving is still relevant if you might have to portage). Her glutes are a bit underwhelming so she gets a very sore behind after a few hours paddling. She was using Klymit’s Ultralight Pillow (which is an excellent sleeping pillow) but it was not quite up to such shenanigans and came apart. Several attempts to repair it with cuben tape and Tenacious Tape both failed. – the only time this has ever happened to me. There was a spot on the material which just kept bursting through again and again – quite possibly a manufacturing fault with the material. This seat should prove better for her next summer when we recommence serious canoeing again. (I hope)
Available here: https://www.thermarest.com/seating/lite-seat US$24.95 May 2019 Dimensions 13” x16” x 1.5” (33 x 41 x 3.8 cm) 110 grams It is a very comfy self-inflating seat (a cut down version of the Prolite mat) and would provide relief on the trail as well if you do not mind carrying the weight. Of course if you were using it for a (short) pack frame and also utilizing it to extend a ¾ sleeping mat then it would count as no weight at all. It would work well with this budget pack for example – or particularly with the short version of the Crown.
PS: I particularly like the bungee roll up: