Their "Mac-ish" trackpads are really horrible. They sort of look like those on Apple laptops, but do not work even half as good. One big problem is that the mouse pointer will move unevenly if you have two fingers on it (if you prefer to click with your thumb for instance). Try having your index finger and your thumb on it, and then move the thumb, and you will see the pointer moving. Later drivers have made the issue less bad, but the pointer will still hove horizontally. Try that with a Mac pad and the pointer will keep still if you move the thumb, which is how it should be to avoid uneven movement.
And also, why the hell do they still insist on having left and right button on the left and right side of the trackpad? It is horrible and erases the border between the two, unless the laptop manufacturer has made a dent in the surface or something. I must say I prefer the Apple solution to this - clicking with two fingers equals right click.
HP was one of those who were early adopters of these trackpads, which ended up with Gizmodo giving them the nickname "HP FrustraPad".