My sister gave me an InStyler several months ago because she bought one and got one free. I have a couple likes and a couple gripes about this I wanted to share with you.
One thing I love is how fast this baby heats up! It's seriously almost instantaneous. It has three heat settings (low, medium & high) and I always just use the hottest.
When you use it, the cylindrical side spins and heats and the brush side brushes and heats.
Supposedly, this is a straightener and a curler, right? Well I can't get it to work well at all as a curler... I gave up on it awhile back. It's awkward trying to get your hair around the cylinder side and then when I could manage to do that, it would basically just straighten/smooth my hair. I went back to using my curling iron.
As far as a straightener goes, it works well but no better than my traditional straightener except that there is no wait time for the heat-up which is awesome because I like stuff to be ready to use when I am.
So all in all, it's a pretty good straightener and that's about it.
Here is a before and after picture of my hair:
I make sure to get my hair all detangled before I use it because the brush will pull your hair if it snags on a snarl. That's fun to say... Snags on a snarl.
It did smooth and shine my hair but any straightener does the same and that's the bottom line here. If you're torn between the two, I'd personally just buy a straightener and call it a day.