Have tried many heaters (got quite a collection), most non thermostatic propane heaters (i.e. Mr. Heater Buddy heaters) use too much propane, even using bulk tanks, IMO.
Non vented heaters, including Buddy heaters, in waterproof tents (i.e. Cabala's Alaknak) can also emit so much water that waking with a cold rain on your face at O-dark-thirty may be a bit of a (unpleasant) surprise.
In spite of it all one of the Buddy heaters would likely be the heater I take if I ever again camp where a heater is needed for more than getting in and out of the sleeping bag... because of its carry handle.
Personally I find that having a good sleeping bag is better than using a heater, 'though everyone is different and should use what works best for them.
Note; I try to maintain at minimum of two 16 square inch vents (one high and one low) when using oxygen consuming devices in a tent... this will vary depending on your heater/device; always use adequate venting!
Also Note; that the "oxygen sensor" system on the buddy heaters and others are sometime finicky at higher altitudes causing the heater not to work/light, or to go out; even with very good ventilation.
Enjoy!