My GS is in the dealers for warranty work and the loaner is this S1000XR:
Without doubt, a bit of a weapon which certainly encourages the inner hooligan as the acceleration (and noise) is a bit addictive - to say the least.
I found myself wanting to change up out of 6th gear all the time and I'm not sure I'd want one as an only bike but I have to say I love riding it.
Spec-wise, it has almost double the horsepower of my own four cylinder motor...