As someone who doesn't own a X1 but does own a massive library of original Xbox and 360 titles, BC has been one of the most compelling features they have bought to the X1 system.
That said, I still have 2 X360s which do a perfectly fine job of running those games and in fact the resolution boost would be lost on me as I play games at either 1080p or below that on various different screens/projector.
But yeah the BC efforts are commendable to be sure.
even on 1080p screen the game would be super sampled, it would still be a gigantic leap.
It's not exactly 500e worth of difference really though is it? I mean for the same money I could upgrade from my 780TI to a 1080TI considering I still play stuff at 1080p it would effectively be equally underutilized power considering I currently can get OW to 300fps @ 1080p but would still be possible to turn on even crazier light effects while at that silly frame rate.
I just mean, for now the perks of an X1X to me include the ability to play games I already can play but with a framerate and resolution which my nostalgia googles already has applied to my memories of those titles :D If I was to go back and play some of the games from last gen right now I would be a little taken aback that GTA4 doesn't look as shiny as GTAV on PS4/PC but still I don't think I'm going to shell out the cash when I could easily get the PC versions of those older titles and do more with them.
I'm certain though that people who don't have a Ps4 or gaming rig would be delighted with all the extra bells and whistles that the X brings to their gaming, I'm trying not to sound too negative on the system while just getting across the point that I don't think it's for me.