I have one and it works well. I got it for when we have a fire ban. I had to use it twice last year due to a fire ban. Got a lot of attention from other campers that couldn't have a fire. Even had the park owners over for a visit to tell me to put out my fire till he saw what it was. It's just not the same without the smoke in you eyes though.
I actually think that it's a grand idea and it certainly doesn't eliminate the traditional fire if you so desire. Most places that we go to are for the surrounding area's activities which will often leave us tired and not wanting to go through the effort of starting a fire or extinguishing it when done. This seems optimal for the way we camp and something to look into.