You can use the CAC-1504 - The Club 3D USB 3.1 Type-C to HDMI™ 2.0 UHD Adapter to connect every 4k TV as an external Monitor to the Dell XPS 15 9550 's thunderbolt 3 / USB 3.1 port
there is no MacBook Pro that can do that, hdmi 2.0 is not known by Apple computers ...
there is no MacBook Pro that can do that, hdmi 2.0 is not known by Apple computers ...
750m is a fine GPU. OP can go 2014 rMBP since 2015 is too overpriced for it's capabilities. It's around 1700-1800 new. I bet OP can get it for like-new at around $1200-1300 which is a steal imo.
I also guarantee you that you'll never use TB3 on your Dell. Skylake is no big deal.
MBP is just a better laptop overall. Portability/longetivity/Higher quality over new-ish features like TB3 and Skylake is no biggie. Also Dell stuff is built out of plastic. The battery is cheap, power brick is cheap, etc. OP can install Windows if he wants. The trackpad on the MBP is second to none. It's a beautiful IPS display as well.
As a student you're looking for value/performance and the 2014 rMBP is a monster.
If OP wants 13" (strongly advise against it, since no dGPU. He/she may want to play a game or two) then it should be around $1100 for a brand new one. But the 15" has better speakers/bigger screen/dGPU/Better CPU. The best the 13" can do is broadwell.