I have used a few varieties of these over the last 7 years or so. Cheap and not so cheap at all, two were over $11k. Glad they were not my dime. Painted several complete cars in them, mostly classics, and lots of parts/fender benders. Did them for myself, friends, and work. Never had a problem with leaks or the power going out with any of them. Would definitely be a problem if it did deflate, especially before the project was dry. They actually go up fast, imo. Taking them down and rolling them up is a whole different story! That does take a little effort. With a helper, I can have one packed in about 20 minutes. The cheap booths are a knock-off of the Carcoon booths. I have sprayed in Carcoon, Mobile Environmental, and the cheap Chinese booths. All of them have major issues. For me, airflow was the biggest problem in all of them. Like sberry mentioned, a standard stationary cross draft booth uses negative pressure drawing air through the booth, usually with a tube axial exhaust fan. Although, you can add an air make-up unit so clean air is forced into the intake. All the inflatables I have used and have seen use a positive pressure system with no good way to exhaust the fumes with just forced air on the intake side. For little parts it is not that big of a deal, but for big projects, forget about it. It is like you are in a sauna. You can not see your hand in front of your face when spraying clear, base is not too bad. Over spray just hangs around and falls into the project creating huge problems. I asked a particular manufacturer what their air flow fpm was within their booths, approximately. I was actually told that they do not care about air flow, they just care about air changes? After I mentioned the obvious that both air flow and air changes are directly related, he proceeded to tell me he did not know the air flow fpm. He mentioned their standard size booth has approximately one air change every 2 minutes or so. Doing the math, that comes out to be about 12fpm air flow. That explains alot. If I remember correctly, stationary cross draft booths, which are the same basic style as all the inflatables on the market, are designed for 100fpm and downdrafts about half that in order to get proper airflow. Then, the size of their standard booths are so small it is impossible to walk around the entire car comfortably unless you are painting a Yugo (or maybe a Smart car if you are one of those young folks!). They usually give you just outside dimensions, not interior. Oh, and then there is dirt. The style with the pressurized cabin before the air enters the painting area (Carcoon and Chinese) is just a nuisance. The blower that supplies air into the booth just pulls dirt from the floor outside and forces into the pressurized cabin area. Then, if you walk through the door into your painting area, dirt just comes right in with you. Learned quickly not to use that door while the feed blower is running. Cheap Chinese booth filters on the intake and exhaust sides are useless, too, imo. The intake filters on the cheap booths I have used would let grains of sand through! Their exhaust filters choke the whole system. I was actually able to get a cheap one working ok with several modifications.
Wow, what a long rant! Sorry. I guess what I am saying is that in my humble opinion, I think the inflatables are a good idea, but the reality of using what available now is not much better, if any, then just making your own booth. I guess they have a place in the industry, they seem to sell. And, I guess nothing is perfect.