Seeing the OP mention owning 3 platforms........its kinda unrealistic for the average gamer, who would just own 1 console per generation. I think MANY core gamers who get multiple platforms neglect this mentality of single console ownership per gen.
Because if you just want one console, X1 seems the best equipped out of the 3. The multiplats/3rd party support alone give it a big edge on WiiU and the exclusives are great and you get many games that have a PC version as well. But considering many dont game on their PC this is just another plus for X1 for being extremely varied in its offerings from a single console perspective.