per pad layers has been reduced to 3 in favor of having ADSR for pitch, filter, and amplitude.
but this doesn't matter, because you still have simult - which of course means that you can have up to 12 layers if you want (though this would be exceedingly rare, as it would be at least 1/3rd of your polyphony.
personally, i'd have been happy to have the number of total layers reduced to 2 or even 1 if it meant more PROGRAM-level control. PAD LAYER is the poor man's simult anyway