I own a Thermarest Neo Air X-therm, it is a true air mattress in that there is no insulation in the traditional sense [foam/down etc]. Mine came with a pump sack, which when expanded, is probably about 6 liters. My stuff sack looks like this:
Ease of use: This system can be fully inflated with the stuff sack, although I find it much easier to adjust the final firmness with my breath. Due to the fact there are baffles of reflective plastic inside, not moisture absorbing foam or down like most insulated air mattresses, the moisture will not degrade the effectiveness of the insulation, or damage it.
The newer upmarket Thermarests come with a much larger stuff pump, that resembles a 20+ liter dry bag, they can fully inflate it from empty in only a few pumps, they work MUCH faster. If your really lazy they sell a tiny battery powered pump that fully inflates it in no time, with no effort.
Comfort: This is subjective, and will depend on how large, and how much you weigh, and the temperature your camping in. My X-therm has an R-value [measure of insulating property] of
6.9. this is vary warm, and is comfortable on snow down to -20 or 30 with proper tent/sleeping bag. anything passed 4 would be sufficient for cool weather, and on hot nights, no insulation is really required. this mattress is 6.4 cm thick,fully inflated. when it is fully inflated it can feel kind of like sleeping on vary hard ground, luckily, unless you need the full benefit of the installation, you can sleep with it partially deflated, and it still keeps you well off the rocks. My model is tapered at the head and feet to reduce weight, and is quite narrow in the middle, this is to save weight, and there are much wider versions available.
Ease of carrying: this model packs down to 23 cm x 10 cm, to visualize, its smaller than my 1 ltr nalgene bottle when its rolled up, and only weighs 0.43 kg [just under a pound], for its size and weight, its easily my favorite piece of gear I own.
Durability/issues: This mattress is remarkably durable despite the flimsy feeling fabric, but I have read accounts of people poping them on sharp rocks. Keep in mind most other similar mattresses on the market have thinner [and presumably less durable] fabric. If this mattress gets a hole you cannot repair in the field [it came with a patch kit], you will be stuck laying on what are effectively 3 sheets of plastic, there is NO fill to provide any insulation or comfort. for this reason, if you are winter camping you MUST bring something for an emergency, you may be able to use your empty pack for this use, but I always carry a closed cell torso pad [just cut one from your head to bottom of your buttox] if I am camping in cold weather were a failed mat could cause serious harm.
[This is intended to give you a general answer to question re pump sack air-mattresses. For reference this pad is probably 2-3x more expensive than the one shown in the video, but most of the considerations are similar. For backpacking I will never go back to the self inflating style]