Read again the R129 note: "known issues are 'disable collisions' doesn't work, and it doesn't currently work if minified (be sure to untick 'minify script' on export for the time being). However you can still give it a go and see how it works out for you."
I try a simple physic example by ashley, with 20 object falling at one to the ground, it's still very smooth with 6x fps, i'm double and double the object about 100-150 objects, it's still 62 fps, i'm using galaxy s2 to testing it... I'm F**king happy right now :(( !!