There's no console bias at least on my case (Mortal Kombat bias if anything
). The fire effects are pixelated on PS3 (check Scorpion's victory pose for reference, or in Test your Luck the X-ray/etc. icons that appear through a match) and Shao Kahn's Throne Room dosn''t run at 720p on PS3 (but is the only arena with said problem).
Digital Foundry noted those things too:
"Interestingly, on one particular stage - Shao Kahn's Throne Room - the overall impression is of a sub-HD presentation on PS3 around the 680p area. We're not entirely sure about the reasoning behind this, as it does seem localised to just this stage, which doesn't look to us like the most taxing in the game."
"On the other hand we see that texture filtering is better on the 360, sporting higher levels of anisotropic filtering (AF), whilst the alpha buffers - smoke, fire and so on - are rendered in quarter resolution on the PS3. However, only some of these effects are actually filtered, leading to visible pixellation in some scenes. "
Contrast/color balance seems better on the PS3, plus it also has more content; which I also noted.