First of all, other than both living in the same state, I have NO connection to this company.
At every one of our state series races this year Orange Seal Cycling Products has had a booth setup with some of their products. After talking to one of the founders of the company I decided to go ahead and give their tire sealant a shot.
So far I have setup 2 brand new tires, 5 older tires, and fixed one flat with it (a pretty thick cactus thorn), and have had no issues! The 2 new tires sealed right up within a minute or two of the bead seating, faster than Stan's ever did. The tire with the cactus puncture was using Stan's but had run dry, put about a half cup (the little red Stan's cup) of the Orange Seal in there and it sealed right up. One of the older tires I setup had issues completely sealing with other sealants, it would stay sealed enough for a ride but would be flat by the next day, put a bit of the Orange Seal in and it completely sealed it, no issues yet.
I only have a couple rides using their sealant so far, one of which involved running over a cactus during a race (this was a different tire than the one mentioned above), afterwards I checked the pressure and it had only lost 5psi before it sealed. So needless to say, I am more than happy with it!
I'll keep you guys updated on how it works out in the long run! Also, it claims to be "World's Lightest Sealant", but stupid me forgot about that until I had already put it in the tires..
UPDATE: As far as sealing holes goes, it was noticeably better than Stan's! Unfortunately, it doesn't last long at all, and as has been pointed out, it's not cheap. Unless you live in a fairly cool environment, I wouldn't recommend Orange Seal. Here in Texas, I was replacing it every 2-3 weeks during the summer (with temperatures no lower than 100F daily), and every 1-2 months during the cooler months. Just became too costly!