Dell XPS 15 vs Desktop

[lexrj1981]

Looking into the Dell XPS 15 (i7-6700HQ 16GB 512GB SSD UHD touch 4K GTX960M) for video editing (1080p and some 4k footage using Adobe Premiere), which I can get it for about $1400. My questions is, If I were to build a $1400 desktop, how much better of a performance would I get compared to the XPS?

 

[Calculagator]

Here's a rough part list I threw together: http://pcpartpicker.com/p/NdKtXL
I would estimate that for the money, you could get around double the performance, especially if you are willing to shop around a bit.

 

[ffg7]

go desktop as way easier to upgrade & repair but is not mobile like a laptop.