incorrect on all counts.
PS3 and xbox 360 support different versions of "3D".
PS3 had HDMI 1.3/1.4 which supports enough bandwidth for two 720p images, which it creates (at a huge frame rate penalty of 50-66% reduction in FPS) TWO vertically stacked 720p images
x360 has HDMI 1.2 (1.4 for new consoles) which does not support a pair of 720p images, instead of a pair of vertically stacked images that get's separated, x360 separates horizontal images that adds up to one 720p image. the images are extrapolated at by the TV to cover the screen size.
What it boils down too, is PS3 3D is a full resolution 20fps or less, unplayable but pretty slideshow.
where xbox 360 has an image quality hit, but maintains a playable framerate.