My reason for upgrading my PS4 was pretty easy. My older son is in college so I sold him my PS4 for 75 bucks and used that money to purchase the Pro. I will upgrade my X1 and make my younger son work for it as he plays minecraft and gets in my way when I want to game. I have a 4K TV and I want to sample some 4K UHD movies with the X1X. Anyway I saved up my money from my birthday last year and this year so the X1 is already paid for just need November to come.
I do believe Sony skimped on the PS4 Pro but it does it's job very well for for enhanced 4K games.