To your point, sebbi said in another thread that Haswell benchmarks will be a good indication on the gains to be had by going with a fast,low-latency, on-die cache. So if intel feels this is the architecture to use for a high-performance multimedia APU, i'm not clear on why some are treating the XB1 design as a consolation prize?
I don't understand the validity of this comparison. Gains to Haswell of the on die cache will be largely due to the more than double bandwidth achieved though it vs a normal DDR3 interface.
Xbone on the other hand is gaining no bandwidth in using esram + DDR3 vs GDDR5 alone.
Of course if we're talking about comparing Haswell GTe vs the rumoured Kaveri using GDDR5m, both with similar overall bandwidth then it might make an interesting analog for PS4 vs Xbone performance (albeit a likely higher inaccurate one!).