I have a Thermarest Prolite 4 and am a side sleeper (no matter how hard I try not to be). I always wake up with sore hips. Friends clued me into the Big Agnes pad this past weekend. I don't have a Big Agnes bag with the sleeve - should I get the mummy to save on the weight or the rectangular to allow me the room to roll on my side and curl up?

I have the mummy. I'm a wild sleeper, but this pad is thick and warm enough that my body seems to know to stay on top of it while sleeping. I sleep in a mummy bag (not a ba / no sleeve) It seems to constrict me enough so that I don't spread out and off of the pad at all. I'm perfectly satisfied with my mummy pad, but with that being said, I'd probably still be satisfied with the rectangular, but lighter and smaller wins me over.

just another perspective -i have the mummy, and thought it would be too narrow towards the tapered end. turns out, it hasn't been a problem at all thus far. i find it plenty wide enough, and i sleep both on my side, and my back throughout the night. i'm 6'1" and 175lbs and got the long. i prefer the slightly lighter weight and less bulk of the mummy pad.

If you get sore hips from sleeping on your side, try this tip I got while in the Marines. Scoop out a shallow trench about an inch deep under your hips. Helps relieve pressure and keeps your spine better aligned.

Definetly go with the rectangular! I have the mummy and i wish i had more room so my feet wouldn't fall off. The only reason I would get the mummy is if i had a sleeve in my bag and if my tent would be too small for a rectangular. If I could buy it again i would buy the rectangular!