thats an interesting question mate
short answer, yes, as far as the guys at totalruckus.com go.
they say the front fairing allows for better aerodynaimcs when leaning down low or 'tucking in'
they suggest the 'gearing' in the mets allow for more customization, smaller drive belt, sharper ramps in the CVT, so in effect you may be able to get faster acceleration, and higher top end, due to the smaller belt can travel further up the 'curve' and the different shape ramp allows for faster acceleration, then you can fine tune it to suit the person with various roller weights, etc(over my head, literally regurgitating their stuff here)
but then again, all that can be interchanged to the ruckus engine anyway.
they are both the 'GET' type honda engine
having said that, i have nfi what parts i would run from which scooter yet, til if/when i get to look at his
his 'metro' is the older model, '02 and seems a simpler design regarding the engine, etc, and has done a lot more kms than mine I'm assuming?
TBH, i am thinking i could simply use his engine/drivetrain with the Metro front, with my Ruckus rear, and bypass whatever is wrong with my scoot as it sits now
also scoring a one of a kinds scoot(as far as i know) in Oz..!