I have used the lemon naturals. They put out a lot of heat but the ash is SUPER fine and blows away at the slightest breeze. Also the chunk sizes is small to softball size at times. So you will be breaking up a lot of pieces here and there. I would like to get some of the coconut ones though.
There are several reviews of the lemon nats, mine is about 3 to 6 reviews down on this page, and there are at least two others past mine and on the next page.