You know, you could be entirely right. The only thing I have to compare to the X400i is the PCX. And the Honda felt a little quicker to me, judging from how long it took me to get across the light at a particular intersection. Then again, it just may be that the PCX was smaller, and therefore just seemed quicker.
In any case, I like the X400i far better than I did the Honda. More room, more comfort, more oomph, more capacity, and just overall more.