I have a few things going on in my head here, in no particular order:
I love the look of your bike, I am tempted as I do mostly motorway commuting and maybe a thou would've been a better choice for me over my 600, purely for the acceleration.
Have you test rode any other FZ1S's? Do you know whether it's that particular bike or just that model you don't gel with, i.e. would the things that put you off also mean it would be a bad decision for me, given I've been riding just over a year?
How is the riding position compared to your 600? The only thing wrong with mine is that my legs get a bit cramped after an hour or so with the balls of my feet on the pegs. I'll be looking for something with a bit more legroom, which is why I'm considering an MT-09 as well. I wasn't even considering an FZ1S until I saw this, it's gorgeous!
And, if it looks like this would be a good bike for me, would you be interested in a part-ex with my 52 plate 600, with say £1500ish your way? I'll give plenty more details if you want a bike this summer.
However, if you get £3k for your bike (I see no reason that won't happen), a £3k deposit at a Yamaha dealer will get you an MT-07 for £73 per month on finance, for only £320.64 on top of the list price. So no need to go without a bike this summer at all.