Not long before we purchased our iKamper RTT (which we love) we were getting to the point of not wanting to wake up crawling off a ground pad and sleeping bag. I did some research and found the Etekcity inflatable bed. When we were using ground tents, this "bed" would inflate to 22" high! It was great when getting up in the morning being able to actually sit upright out of bed to stand up! As you get a little older, getting off the cold hard ground in the morning is not as easy as it use to be.
But also on that note, and to segue to your comment about not needing air in the middle of the night.
The reason ALL mattresses seem to feel deflated in the morning is NOT because of a slow air leak, although, I'm sure that is the case sometimes.
What is really happening, especially in higher altitudes or colder climates, when one inflates their air mattress, it's usually done in the middle of the day, nice and warm out when setting up camp.
Well, the colder it gets through the night the more air compresses (think inter-coolers for turbos) and the air in your mattress sucking up all the coldness from the ground. By around 4-5:00 am it is just about it's coldest outside, thus all that nice warm air you pumped into your mattress when if felt really firm, is now sagging like a bad facelift. So you go and fill it when it's really cold and by the middle of the day, you risk the possibility of bursting your mattress as the warm air expands.
So when you say your air mattress always stays firm, I have to think that is because you don't have it on the ground where there's a lot more cold thermal contact than in your nice warm vehicle.
But all-in-all, nice setup!