And with that, there is almost no need to top up the tires with air. I didn't have much of a problem with this using Stans (29er mtb tires) but Orange Seal on fat tires was a problem child, needing air about once a week. Flatout, on the other hand, has been something of a miracle. On my BFD, which has had the same load of FO in it for somewhere in the ballpark of two years, I originally could let the bike sit for a couple of months with no air loss of any kind. Now, the front tire has I guess stretched its casing enough - or something - that the front tire needs about 5 psi every month. The rear tire is still perfect for as long as I care to leave it. On my Apostate, its full load of FO is keeping the tires up to their max of 60 psi for a couple weeks. Give it a month and I am down to 40. Thats just as good as a tubed tire with Flatout inside doing the same slow-air-loss reduction job.
You are still screwed if you put say a 1" hole in the tire, but even with a tubed setup, I ALWAYS carry a spare tube. With tubeless, all I need thats extra is a towel to wipe off with after fussing with that muck inside to get a tube in.