The straighter works well on hair that many other straighteners would struggle with. Thick, curly hair can be straightened extremely well and go a couple of days without needing a touch up.
A common malfunction of the product is a gap between the two plates, getting larger towards the handle. Because it can't squeeze closed on your hair, it might not straighten properly.
Lots of reviews stating that their CHI stopped working after less than a year. In some cases it just stopped heating up or turning on, and there has been many mentions of a faulty cord.
Some people have found that this straightener malfunctions not long after purchase. Either with parts (like the silicone strips) falling off, or it simply stops working.