Thanks a lot for your replies everyone.
I mainly want to complete my 8th gen console set to be honest, already have the rest of them including the WiiU.
The games that I really want to play are the Gears of War Games and replay Ninja Gaiden 2 in 4K. Although if i do get an Xbox One I would definitely pick up the GamePass. Dont know if it is reason enough to spend the extra cash. Unless the 4K experience vastly superior to the what I have now.