The major limitation of the xbox one really is that 32MB of ESRAM. Same amount as wii u which is a far less capable console. We have seen games that initally release at 720p but are patched to 900p later or 900p to 1080p. This is the result of having to optimise that 32MB of memory to fit everything in. It's simply a limitation the ps4 doesn't have, not only is the gpu about 40-50% more powerful in graphic cores, but it is 2x capacity in rendering output and has full access with no restriction to incredibly high bandwidth GDDR5 memory. This bodes well for 4K support, full use of 1080p, 3D support and their upcoming VR visor.
There will likely come a time when more casual gamers start to realise the huge difference in power and the xbox one price premium will become unsustainable and may even fall below that of the ps4.
I saw Forza on display in store on xbox one. There was some aliasing on what I'm sure was a 1080p display. I was not impressed. Car models were nice but the general look of the surroundings, sky etc still looked last gen.
