my brother has a xps16 which is a perfect laptop for him as he uses it as a desktop replacement . it has all kind of ports ,the screen is also good (afaik its 300nit) but the ppi is too high for 16" screen .the high resolution wont be much of a problem if you are going to use win7. i dont like the laptop much as its too heavy , core i7 is power hog buy it only if you are going to use that kind of apps .
i bought a envy 14 over the xps16 . the laptop screen is the best i have seen (only 1 step above xps16 - you can tell it easily just by looking at it) . the cooling is excellent and it doesnt overheat even when operating on a mattress