I purchased a Therm-a-Rest NeoAir Air Mattress Large before this Exped Synmat 9 Deluxe. The NeoAir is great (19 oz, packs small) but mine began to leak through pinholes at the seams after about 10 uses. To Thermarest's credit they replaced it (with a refurbished one) quickly. However, in the mean time, I purchased the Exped SynMat 9 Deluxe.
Frankly, the Exped 9 seems like it is built like a tank compared to the Neoair. The Exped weighs 23 oz more (42 oz vs 19 oz). It is 1 inch wider (26" vs 25") than the Neoair. It is also 1" thicker (3.5" vs 2.5"). The Exped 9 has an R value of 6 vs R=2.5 for the Neoair. The Exped 9 Deluxe has a built-in pump, a repair kit, and a stuff bag--the Neoair has none of these "extras." The Exped 9 is also at least 50% more bulky when rolled up, than the Neoair. I have no trouble deflating/rolling-up either the Exped 9 or the Neoair. While the built-in pump of the Exped 9 works, I use a Coleman 4D pump to inflate both air pads. To top each off, if necesary, I use a few puffs for the Neoair and a few pumps w/ the built-in pump on the Exped 9.
Considering the bulk and the weight of the Exped 9, it is very suited for kayak-camping or car-camping. Some backpackers do use the Exped 9.
The Exped 9 provides a GREAT NIGHT'S SLEEP (the NeoAir does too if it does not leak.)
I kayak-camp about 20 nights a year--mostly along coastal Everglades during the winter. During the summer-fall, I am in the rockies at 8000-9000' where I usually camp 25+ nights at temperatures into the low 20s. I do numerous multi-day trips into remote areas where it will be very inconvenient if an inflatable mattress fails. For this reason, the Exped 9 is my hands down favorate for back-country camping.