Mine's a size XL, and it's 30" from the top of the collar, to the bottom of the vest.
I have a fairly long torso, and it fits me fine.
I'm about 5'11 and 220 pounds, and the XL fits me well. I have an ex-weightlifter build with some extra belly now.
Pick the size that's a little on the large side for you, because the vest needs to have some room to pump up. If you get your normal chest size, it will be too tight when you pump it up. Also, don't pump it up like a life vest. Just enough to give it the "loft thickness" that you want is all that's necessary. If you pump it up hard, it gets too stiff, and is uncomfortable.
The key to sitting down comfort is not having it blown up like an inflatable body splint. This is easily avoided when using the air inflation instead of the argon, because I'm not trying to "conserve the argon" by using the same level of inflation for everything. With the air inflation, you actually start using the adjustability of inflation, and it all comes together. When trying to conserve the argon, it impedes the versatility because you don't want to let any costly argon out if you don't absolutely have to.
The air is much more versatile because it doesn't have this limitation of trying to not let out any gas.
The other thing is that when it's deflated, it hangs away from your body, because you have that extra size room in there to allow for inflation. So, it allows air movement to get under it, and doesn't act like a rain suit. Again, I think the key is to not get too small of a size. Having it hang looser on you when deflated helps air to circulate under it.
I got mine for $83.45 on line. I had to take the amphibian model to get that price, but I found out that it was not actually that chartreuse green that it appears to be, and it is actually a fairly nice earth tone olive drab color. I am pleased with the vest, especially at that price.
I am also pleased with my Klymit X-Lite inflatable sleeping pad.
I think these guys have some good products, and the technology works. Sometimes it seems like they understand the need for low weight with the sleeping pads. But then they don't grasp the low weight issue very well with things like this Ulaar, and think that things like "bamboo carbon liners" are somehow going to seem relevant to the consumer. I can't figure out which consumers those might be.