A liter would destroy it… i doubt this thing would even be in modern 600 territory to be honest (as they are well into the 10s now)
That rear tire looks huge and putting down ~180 hp based on a zx-14 with all the extra weight… i think it would be a massacre (in favor of the sportbike)
Fun factor for 2 up riding, obviously goes to the trex though… comfort of a seat > a bike.
0-60 in 3.5 is fast for a car, but for a bike, its quite easy to get to 60 in a little over 2 seconds…