When I first got this, my medium-long, thick, slightly wavy hair was all one length. Since it tends to get frizzy and I'm not the biggest fan of flat irons, I decided to give this a try.
This doesn't really do what I'd call straightening. Straightened hair tends to look like it's actually been ironed. It's flat, sleek, and smooth. This tool did tame my frizzies and fly-aways pretty nicely, but it doesn't give that flat ironed look. There's much more volume with this than with a flat iron. So if that's the look you want, i.e. reasonably smooth but with lots of volume, definitely give this a try. If you're looking for actual straightening, you're probably better off with a proper flat iron.
Since I got this, I got my hair cut. Had some of the length taken off, though it's still past my shoulders, and I had textured layers put throughout. And now, this product isn't that useful to me, unfortunately. The layers make my hair much less prone to frizzing up (the layers curl instead; when the hair is long, the weight prevents the curling and just gets frizzy-puffy), so I don't need this for that, and, as I have never managed to get the "curling" aspect of this device to work for me, I can't use it to shape the layers (and I have the 1.25"/32mm version and the barrel is too big to do much for the shorter layers).
I've been using curling irons, hot rollers, regular rollers, and all sorts of other hair appliances for 35+ years now, but I just cannot seem to get the twirling motion needed to make a curl with this thing. I can use a clipless curling wand perfectly, no problem, so I definitely know how to wrap the hair, but this? Nup. Can't get a curl with it. Have reviewed a number of websites and I don't even know how many YouTube videos trying to figure it out, and it's just not happening. Well, actually, on a couple of occasions I've managed to get a bit of a curl going, but any curls or waves I do manage to get don't last long, sadly. So as a curler, I have to say this is pretty useless for me. I know some people absolutely love it and can make amazing beachy waves and who knows what else, but I just can't seem to get it, sadly.
So, for me, there's no way this is worth the full asking price. It's okay to get rid of frizzies and does a reasonably good job of that, but that's all I really used it for, and it's actually not my favourite tool for doing that, mostly because this, with the rotating motor, is on the noisy side (my favourite tool for smoothing my hair is an ionic heated round brush). This is an okay tool, but I'm glad I got it second hand on eBay rather than paying full price for it new. If I had paid the full price, I'd feel really ripped off. I may, one day, work out how to do waves/curls with it (I'm going to keep trying!), but like all products from this company, it's way overpriced and somewhat overhyped.