depends upon budget,, if u have +/- 725KRS then u can buy vxri,, i ve not owned vxri so cant recommend u, i have carby 2007,, used to give me 200km/tank,, with a very light foot,, but now, after clutch plate replacement it gives 200km/tank even on hard foot,, so there is no issue of efficiency,, maintainace is cheap,, carburetor service requires after 40K km