I was considering using one in our tent. We have a huge 15'x10' tent that we figured had plenty of room to keep a 2' radius around the heater. Of course we wouldn't leave it running unattended or while sleeping, and would keep a fire extinguisher nearby. However if they are really that prone to catch fire, I might rethink that. I know lots of other people who do it.
Yea I had no qualms using it in our tent, the flames are very well contained within the unit & appear to be little more than just a glowing sheen over the ceramic heating element.
But I'd really like to hear more about both of Singlestack's bursting into flames before I use ours again though, there had to have been some sort of catastrophic failure of his heaters pressure regulators or a very big propane leak or something.