I've always heard people rave about GHD so my expectations were very high. When I first used my GHD I was expecting god like results - which is probably too much for any product, especially if I am the one wielding it!
Each time I've straightened my hair with this it lasts only a few hours, even if I do a thoroughly good job of it. Despite following tutorials and using specialty products I have never seen long lasting results. While I think the GHD is head and shoulders above the competition I found that even it was unable to keep the ends of my hair curling after a few hours.
On the positive side, I found that this straightener dries my hair far less than other straighteners I have tried and I think it does a great deal less damage. I would say it is a good product, as it heats up quickly and is well made, but it's not a miracle worker.
I have used this pretty much everyday for the last 3 and a half years and surprisingly enough I get compliments on how my hair looks so healthy. It leaves the hair soft and shiny and lasts from the time you straighten it to the time you wash it, I have quite thick wavy belly button length hair and it does take me about 25 minutes but for the job it has to do, it doesn't seem so long
Tips: I would recommend a heat protector because there's no way that much heat to your hair everyday is good for you