I got mine for christmas :-) Only experimented once and might need another go but am very impressed. My hair is fine and flat and gave it a good boost, be careful to hide all the crimped bits tho had a few people on christmas day asking what on earths happened to my hair haha!
I got one for my best friend for xmas(she has very very flat hair), her hair takes on average 1.5 hours to do every day, she has to seriously muck about with it to get any volume into it at all. She has RAVED about the Root Boost since xmas day. She absolutely loves it and would recomend it to anyone!
I stupidly let my mum use mine on my hair and she did one batch at the ends (to see what it looked like) DO NOT TRY THIS !!! It sizzled my hair - am very dubious now about using them for anything - will try again soon .....
the reason they done that though is that you had no heat protection, when you use them you should use them on the lowest setting (then adjust if needed)and as with any straighteners/curling wands etc you should use heat protecton to prevent frying your hair!!