The following comments are for the "double". I also have the single (78"x30"), and the comments are at the very end.
I got this pad (double, 79"x50") for my wife and I, for tent/car camping.
DOUBLE WIDTH:
When received, the pad's rolled-up dimensions were 26" long and 12-13" in diameter. The storage bag seemed extra large, but these dimensions grow (to 15-16" dia.) as the pad can't be re-rolled nearly as tightly as the factory process; so the storage bag ends up being the right size.
The initial self-inflation was taking longer than I cared to wait, so I used my mini air pump - which quickly did the job. After the pump seemed to stop adding anymore air, I put in a few puffs by mouth to fully inflate it. I let it sit for a full day to make sure it reached its full expansion. For the several days it was inflated, and when I slept on it, there was no sign of any leaks.
I measured the thickness to confirm the claimed 4" (3.9") - I could only find a thickness of 3.7" (at most). As the top surface of the pad has the "3D" pattern, 3.7" was measured from the bottom to the peak of the 3D pattern. (to the valley measured just under 3.4", with 3.5-3.6" the average between peak & valley.) You could argue which dimension is appropriate, but no dimension reaches the claimed 4" (3.9"). This is unfortunate as it's one of the most important factors in determining how comfortable the pad is.
I find the pad too firm when fully inflated, so I need to let some air out. This does increase comfort but further reduces the pad's effective thickness. So if you let too much air out, and sleep on your side, you can start to feel the pad's memory foam start "bottom out" beneath your hip and shoulder. This was not uncomfortable, but might lead to a "cold/cooler spot" when used in cold temperatures. So it's best to experiment and let air out, to the point before your hip/shoulder fully compresses the foam. I slept on the pad on a hard floor and therefore did not test anything about the pad's cold weather properties.
While having a "full size" mattress sounded like a good idea, when it came to rolling up the pad I realized it simply takes too much effort. I've rolled up other self-inflate pads before and none were anywhere near this difficult. With the valves in the deflate position, it takes a lot of pressure for them to pop open and let air out. I'm 5'-11", 175lb, and as I rolled it up, I had to put every bit of my weight onto the pad before the valves popped open and released some air. Sometimes it was easier to lay my entire body on the partially rolled pad, and simultaneously flip one of the valves halfway to get some air to rush out - then quickly close it before letting my weight off. It's a real fight getting this rolled up. I think the valve discs need to be made of thinner material which would deform more easily to release air.
Anyone familiar with self-inflate pads knows that it helps to re-roll the pad a second time to squeeze out as much air as possible, and achieve a nice tight roll. I needed to re-roll this pad 5 times just to achieve a roll which fit back into it's bag.
For Comfort, I'd rate the pad a 4.0-4.5. For Convenience though, due to the difficulty rolling it up, it would be 2.5
SINGLE WIDTH:
The thickness of the single is comparable to the double, so it's not the claimed 4". Despite that, it is a comfortable pad like the double size. As most of my comments about the double apply to the single, I'll focus on the big difference - rolling it up.
The single is far far easier to roll up than the double - truly, a pleasure by comparison. To anyone considering the double size, I'd recommend 2 singles instead. Yes, it costs more, but I think it's worth it. Of course 2 singles might not physically fit your situation. My 2-person Naturehike Mongar tent just fits the double but will not fit 2 singles, while my 3-person Nemo tent will accommodate either.
When my wife and I tried the double size, we did not find that my tossing/turning disturbed her very much. It's nothing compared to the ocean feel that comes with one of the large inflatable mattresses. Still, having 2 separate pads eliminates this issue entirely. And each person can adjust the amount of inflation to suit their preference.
My overall score for the single would be 4-4.5, compared to a 3 for the double.