i drive a vios myself.. all i can say this car is powerful in its class (1500cc). Of course u cannot expect a <90K car to perform like a BMW but to hell with it, this car is good for city driving and occasionally rembat-rembat around especially if you do mod the car.
I've got 2 vios in my house and one has some minor modding which is mine (eg. Pivot VS-E, HKS drop-in filter, 16" Sports Rim, front + rear strut bar) and it performs better than the stock one in terms of pick-up. Meanwhile, the stock one doesn't perform too bad either, i've managed to clock 180kmh on the highway but it was too wobbling due to the stock tires and without those strut bar, while i tested on mine and can reach 195kmh and it can still goes but my balls aint made in USA.
Another thing is the Over-Drive, find out that vios 3rd gear is very powerful (and like other forumer mention, is its gear ratio cause the 3rd gear can reach 180kmh and without red-lining yet to my suprise)
Once i manage to outrun a L200 on traffic light and a waja 1.6 (auto, if manual will definitely lose out on start).
Conclusion, this car is good for town driving and to those who occasinally love rembat rembat around town but if u going to compare this car with K20A or 4G9x or K3VET i guess the answer is shown before the comparison.