Nothing drives like a twin, mate. A twin has torque, low and mid end power, and if it's a 4 valve twin, it even has high end power. Once you rode a Honda SP1 or a 916, 996, 998 or SuperSport from Ducati, every other japanese 4 cylinder bike seems empty, without taste and without character.
Of course they are powerful, but what's important on a bike is the feeling and the character : and nothing can beat a twin. And fook me : the SOUND of a twin !!!! (if you want i can make you hear one of my Ducati with free carbon exhausts )
Not to speak about design, in which of course Italian bikes are far far above japanese bikes, on which they change stickers colour every 6 months and you feel like your bike is old fashioned ROFL
To finish, find me a better looking bike than the Ducati 916 / 996 / 998 family
But keep in mind they are really tough and precise machines, very hard to learn at the beginning, harder to ride than jap bikes, but much more efficient once you know how to use them. Their chassis is much more precise, handling is far above what japs can do, but on the other side they are harder and less comfortable... it's a choice
Remember what the great Giacomo Agostini said about bikes : "a 4 cylinder is NOT for bikes, it's a car engine."