I have used the ThermaRest version of one of these for long time and I really like it. A pillow is a necessity for side sleepers. Maybe because it is 10 years old I find mine does flatten out after a couple of days use. Fluffs right back up in the drier though. The main problems with them is they are a bit heavy and bulky and personally I find it thinner than I would like so I also used an inflatable pillow. My previous cheapo inflatable started self deflating after I tried using it as a sit pad so I replaced it with an off brand pillow similar to the SeaToSummit Aeros. The combination gets the thickness I want but it's not ideal since the pillows tend to migrate even though the inflatable has a strap. I haven't tried the tee shirt over the pillow and pad trick but I'm not sure about the armpit next to the nose factor that seems inevitable with that arrangement. Seems that something dedicated to the purpose is required. A friend of mine has a down pillow with an inflatable core that packs up very small. I think it was a bit expensive though.