I believed the hype many moons ago and purchased the Instyler because I was curious and the models on TV made it look so easy. At the time I had shoulder length hair but quite fine and at times dry.
The Instyler did my hair no favours, in fact I think it burnt my hair - and it definitely caused a few burns to the hand from the awkward way of holding it and getting my hair into the device. Even with the protection cage I would also manage to burn my ear!
The rotating curler if it catches your hair at the wrong angle pulls and tugs, and brings back childhood memories of my mother untangling my hair before school. I don't know if it was the enthusiastic way it the cylinder rotates against the brush, or the fact that my hair was fine, but there was always hair left in the brush after use - which after a while was a real concern.
I could get something that resembled a curl from the Instyler - but was more like a kink of a wave, and I could never master straightening with it at all. It was just lots of fluffy hair. It never replaced my straighteners for straightening my hair.
I never tried the hottest heat setting, for fear for my hair and my ears, and the lowest setting was okay but still seemed quite hot. What I did notice, was the styles when I did manage something suitable for public viewing never really held for long through the day.
Needless to say I wasn't impressed and suspect it's better suited to those with longer hair and a higher pain threshold than me.....so now my Instyler sits on the top shelf of my wardrobe, wondering if it will ever see daylight again. Which it likely won't.