Owning both, I can honstly tell you it is a very very difficult call, for power 1000 wins hands down, but the less weight and nimbleness of the 600 is something that is very very hard to beat and as mentioned 95hp is not to be sniffed at in the right hands..
The 600 needs to be worked through the gearbox to get the best out of it but it is probable the most fun. The 1000 needs more work on the suspension to get it to its best.
I love the 1000, I have put a lot of work into making it as flickable as the 600and it is very close now, but the 600 still brings out the extra little bit of hooligan in me more than the 1000 I think.
As standard the 600 Fairing gives better protection from wind at highish
speeds than the standard 1000 one.
If I was asked to sell one,
I don't know what I would do, as both have very good points and hope I never have to make that decision.
The 600 without out doubt is cheaper to run, but do we care but outside that???????.
If anyone is trying to deciding which to buy, try and get to ride 2 well sorted ones with good tyres back to back and you will find it is a very very difficult decision to make.