Couple of things, here.
No. 1, Richard agrees that Killzone 3 and Motorstorm Apocalypse are the best 3D games out there, even better than Crysis 2.
Both versions are supposedly the same, 360 seems to run at 1152x720. The PS3 version, however runs at 1024 x 720 but the differences are minor, due to blur effects.
The PS3 version seems to have better 3D effects from what I have read. I maybe wrong so you may want to check it out.
The PS3 version maintains its frame rate throughout the whole game even though its lower than the 360 version. The 360 version however has frame-rate going below 20 fps in some scenes. What this means is that the PS3 version operates more consistently then the 360 version, but the 360 version seems to hit 30 fps a lot more.
There is no screen tearing visible on either consoles.
Which is why he seemed to think that either versions are equally good.