I can vouch for the Propex. Works great in an Eezi-Awn Globetrotter. IMHO, the thermostat is a necessity. The thermostat keeps the tent at the right temperature without wasting fuel. (i.e. opening a tent flap to releasel the precious warm air you just paid to heat.) I also like the fact that the Propex allows you to return air from the tent to the heater. This uses less fuel by reheating the warmer air from your tent and also helps take the humidity out of the tent. Just my $0.02
Those Webasto heaters look like the cats pajamas. I would LOVE one for winter camping, but have a bunch of other stuff to do first. Next year maybe?
Greg
http://www.webasto.us/general/en/html/8243.html
You would need a lot more than 2 regular-sized batteries to run an electric heater all night. The dinky little electric heater above pulls 13 amps according to the instructional manual.
The Propex uses a surprisingly low amount of propane, I borrowed one from a good friend, and used it for 2 nights in Death Valley in January, had the heater on all night, but with the thermostat, it doesn't run the burner all night. I have a fiberglass propane tank and the usage was barely visible.
I'm saving up for a Propex.