it's worth noting that today clevo have updated their site, look at the notebooks on the left hand side. before they had the D470W only (the 4760). Don't ask me if there are any internal differances between the D470V (4780) and the D480V (4880?) because I didn't know the models existed until today.
The 4780 is 393(W) x 275(D) x 37.5(H) mm, 15.5"(W) x 10.8"(D) x 1.5"(H)
. 4.2Kg with 8-cell battery. The HP looks to have a similar amount of plastic bezel around the screen, but it looks a lot fatter. HP don't have any size on their website. Maybe they think people will be scared if they know the size? They do however list the weight at 9.3lbs, the 4780 is 9.24kg, almost identical. Remember that these are both big notebooks, but please please don't even consider that hunk of **** HP. (It doesn't sound like you actually are anyway).
If you don't like how heavy it is, or how big then maybe you should consider the 4080, which is a 4780 with only a 15" screen