this is a bit out of date, yes some of the sony vaios are a bit gimicky and cheap but the one I reccomend is a more rugged machine with magnesium chassis (the same as the Dell). I have experience of quite a few Dell as we have 200 of them at work mainly Latitudes and we have found the quality on these have declined over the past few years with failure rates increasing on the more recent purchases. The XPS is a consumer model and with the ones we have tried it has about the same build quality as the Sony FW50 series. Usually the Sonys are more expensive but as I pointed out this one is on special at £700 instead of the list of £900 to 1100 so is a good deal. If you want rugged we have found IBM are pretty good and when you see the state some of our laptops get into on site it looks like they are used as body armour.
My reason for going for the Sony was that the build quality was "good enough" BUT the display quality is very good. The only one that came close was the Dell XPS 16 with the high def 16" RGBled display but that put the price through the roof.
I suppose time will tell