I bought one on the basis of the big thread raving about them.
I'm not overjoyed and dont really use it - but I haven't been doing much at all lately as I've been seriously ill with pneumonia so time will tell. But from the couple of times I've tried it, I suspect its nothing I cant do with my hairdryer and round brush, and in fact I think I get more control and heat from the hairdryer and round brush. Its all a faff though, I have long hair that needs doing in sections and whilst its reasonably fine and well behaved hair, there's lots of it.
I'm thinking of losing some length soon and having more defined layers put in and will try it again after that. I wouldn't even rule out a bob in a year or so and therefore am going to hang onto it for now. But at this stage I'm not convinced it wont be just another gadget gathering dust.
I keep going back to curling with GHD's for my volume and movement, its the thing that lasts days and is foolproof...I just need more volume at the roots. Have used the root boost for that too and that gives excellent results if you sort of rake through and spray the roots with hairspray too - best root lift I've ever got.
I do chop and change a bit though.
Most people do find it fairly life changing. If you aren't already able to do fairly impressive things with a hairdryer and round brush, then its definitely worth a try.