I have a flame heater while a neighbor has a radiant unit from the same manufacturer (Vanguard). According to the literature, the open flame unit will heat the air which, in turn, heats objects within the warm air. The radiant unit supposedly heats objects which, in turn heat the air.
My neighbor doesn't use his much anymore because he finds it to be ineffective. I love mine. However, I have never really compared them, I'm just going on what he's saying.
How may sq. ft. do you need to warm? Forced air might be the most efficient method. And, definitely replace the unit with the cracked h.e. I don't want to read about you being overcome by c.o., in the Sun-Times.
EDIT: I installed the unit in my garage. Not hard at all. However, if yours is mounted from the ceiling, you'll need some sort of lift. Working on a ladder is a no-no. The piping isn't as hard as you would think. The t-stat wiring should be pretty straight forward.