So... I just traded a 2013 ZX6R in for a 2014 Ninja 1000. These bikes are extremely different. For everyday commuting use, the ZX6R is an absolute back-breaker - especially with a backpack on. If you have a long commute, you'll start to feel the hurt everywhere. It's an amazing machine, and loves the twisties. The 600-class power and heavy engine braking help greatly to reduce entry speeds, encouraging throttle through the turns. By contrast, the Ninja 1000 is noticeably heavier, and has almost zero engine braking (at least from 7k RPM and lower). I could go on forever, but the experiences are as different as night and day.