I don't know if it was changed in daily builds, but in alpha, body objects renders significantly different than in mental ray or scanline. In corona, one have to crank rendering aproximation settings much higher to match MR output. And MR somehow adjust triangulation depending on render size (the higher render output size one chooses, the more faces, body object will have on render), whereas corona always produce constant number of primitives depending on rendering aproximation settings in body object.
I understand that such things is very low on priority list, but hopefully in distant future it will be fixed...