I tend to think these are yet another of the annual new cooking devices you see being sold. Popular for a time, then people decide they don't really use it enough or it is limited to success with a few specific products. I thought if you have a convection oven it accomplishes basically the same thing.
in the meanwhile I need a new oven/stove and I'm going to get a convection oven....maybe if I had big counter space,I'd be more able to try it out...