I've been using this for about 6 months now and I like it a lot. The DevaDryer itself is great, and the green hand diffuser is wonderful for going in at the roots, particularly if you clip. I also use this to do a sort of ruffle-dry (upside down) for a quick and dirty soft beach wave.
There's definitely a learning curve, but I'm very glad I've taken the time. I still use my bowl diffuser 85% of the time, this won't replace it for sure, but often go in with the hand as a finishing tool.
I have fine but very dense Botticelli/3a curls at collarbone.