I had previously bought the smaller GHD IV(1-inch styler) at Sephora, but returned it because: (1) it was too much $$$, and (2) it rolled on its side when I put it down on the vanity.
I am glad that I got the wider version on Amazon.com because I got a better price (although the price on Amazon.com has increased $40 since I bought it 2 days ago...), and since it is flat, it does not roll when I put it down.
I am able to get my hair stick straight or curl it for more volume (watch the instructional videos on GHD's website, as this model does not include the DVD). I am able to style my hair very quickly with only 1 pass, so my hair is not exposed to long periods of heat (like with a hair dryer). It is not a heavy styler, so your arms won't get tired either.
I was also able to register it on GHD's website, so this product is legit. Like other reviewers of this brand have written, make sure you buy from Amazon.com and not a third party. That way if the registration does not go through, you can return it hassle-free to Amazon.com.