I brought this bike for the great options it offers. 22 litre tank, tones of storage under seat, comfort.
The GSX 1400 is an excellent bike to do just about anything you want.
The handling does rely on having a good set of tyres; personally I use Pilot Powers, they are a quick warm up and good gripping tyre for this bike. Don't worry about the mileage you get from these, it's all about staying upright.
As for the power and torque, you will love it.
This bike pulls right from down low in the revs to approx 7 grand.
The motor is bullet proof, and if you are worried about keeping up with your sports bike mates, trust me, if you can ride they will be well impressed with you, as you put a lot of them to shame.
As for the comfort, not only do you arrive with a smile on your face, but guess what, no back, neck or wrists are aching.
That's one one the best things about this bike, you don't get left behind too often.
Six pot calipers work very well, but there is always room for improvement. IE braided lines.
To sum up, this bike would have to be the best bike I have owned, the power and torque are just fantastic, and it's a great bike to make your own, with all the after market parts you can get for it.
Don't think about it, do it, you will not regret it.