The Buddy heater puts a lot of water in the air. I prefer the CAT because it vents the combustion gases to the outside.
There are four downsides of a Buddy heater:
1: Needs to be kept well away from flammables. I was camped at a place where someone's popup tent had a heater that caught fire, blowing up the 1# containers. Having the county sheriff wake you up and get ready to evacuate at 5:00 in the morning isn't a good thing, due to the explosions. Thankfully the owner of the pop-up got away unharmed, but it did leave a crater.
2: Needs ventilation. I don't trust my life to a cheap detector, so I believe in at least two CO detectors, one of which has a PPM gauge. This means ventilation in and out.
3: They put out a lot of water in the air.
4: You can either use the one pound propane bottles which last 3-6 hours, or plumb a LP gas hose to it. If you plumb a LP gas hose, I highly recommend putting a petcock near the tee intersection, just so the heater can be disconnected and the hose capped off for the summer.
The good thing is that the Buddy heater is extremely economical. It puts out a lot of heat... but I consider it a last resort compared to the RV's propane furnace, a plat cat, or an electric space heater.