Lightness and piano action are worlds apart. A solid, tight keyset is used by all the manufacturers on their HIGH end stuff, so why don't they think it's important for all players ... Hmmmm?
Piano action has nothing to do with synth action, and a good synth action has nothing in common with ANY PSR product ever made. (with the exception of he 9000Pro, but I'm not 100% sure if it was or was not part of the PSR family - it's not printed on the KB as such)

I hardly ever play acoustic pianos, but even in my Rhodes days .... the heavier action was part of the expressiveness. Today's PSR action is lacking in that area - sure, the sound engine sounds great, and all the bells and whistles are made to perform well .... it's just the touch that drives me nuts. No solid landing at the end of the key stroke - no firm feel under my fingers - skinny keys .... too many things to cite. Fact remains - aw ... who am I kidding ... there are no facts here - just opinions. Mine is that Yamaha is cheating it's MOTR buyers big time. Until they make a keyboard that feels as good as their high end stuff (and HAS speakers) - I will not be using their product.

great example - accordions had NO slop!