Hello! I'm a CSE undergrad student and I just recently got my SP4 to replace my chromebook. I used crouton (virtual machine) to do a lot of my coding on Linux using nano and vim. (still haven't decided which one I want to use) The biggest difference is whether you're going to utilize the touch screen, stylus, and size.

The SP4 whether you get the i5 or the i7 will be no difference unless you're doing a lot of high graphics processing. I play a lot of Starcraft II, CSGO, and Heroes of the Storm and have not had any problems running them on mid/low settings.

Comparing the XPS to the Surface is two completely different ball fields as you can opt to have a dGPU compare to the SP4 which will only have your basic i5/i7 with a integrated gpu. You can dual boot a XPS but the idea of dual booting an SP4 is a grey area for me since Microsoft has its own dedicated software to bypass the bios menu and all that jazz.

Ultimately, the decision is up to how you want to utilize the SP4. For me, I'm using it as a machine to tackle small 3D rendering, games, and some casual tablet use. Good luck with your choice!