Are rice burning stoves more efficient then nut stoves?

Whats the difference between stoves that burn nut and stoves that burn rice sized coal? I seen a stove burning rice at a stove store and seemed to me that it was much more efficient. Unlike my stove that burns nut and must be full, this stove had a small burning pot with only a few hand fulls of rice burning, looked very similiar to my dads pellet stove. And the heat coming out of it was unbelievable.

steve

I'm not so sure, it's smaller burn area but it's also burning very fast. I've heard both are more efficient from different sources but I would put my money on the stoker. It's a even constant heat, even to the point where it won't come on unless you need it. Rice coal will go out without a draft.

My stove has a feed pot and can burn up to 8 lbs an hour but it runs most of the time at 2.5 lbs an hour.
It takes some cleaning to keep it working but I get a complete burn with little or no unburnt pieces.
It heats 1700 + sq ft to 70 degrees on all but the days it is singal digits.