As someone who's owned one for the last five years, here's my observations:
Yes they drink fuel (150 miles to the light... if you're lucky, worst i ever got was 115 when green laning) but who cares.... they're fun!
The side stand bolts to the engine, a potential for major damage, fixed mine with a Charlie's Side Stand relocator (bolts to the frame).
As has been mentioned the brakes aren't the strongest out there but OK as long as you always use front and back brake together.
The standard pipes are heavy and run very hot (right under your bum), that's why I went for Akrapovics
Clutch slave cylinder is almost guaranteed to fail, mine did at 25,000 replaced with an Oberon = problem sorted. And it's an easy job to do yourself.
The starter relay can fail (mine did) as it gets covered in crud being located in the belly pan. Not expensive to fix (about £30 if I recall).
The wiring to the ignition switch can break inside the insulation where it exits from the frame behind the right hand plastic cover (just behind the head stock) because it clamps the cable and doesn't allow it to move. Simple solution is to cut the plastic cover back to give the cable room to move or as I did just remove the covers (you can hardly see them anyway). I also extended the cables (as yes mine broke).
When the front tyre gets part worn they have a tendency to "shake their head" if you take pressure of the bars especially when decelerating, this is normal and due to the steep head angle. You just don't let go of the bars :whistle: A steering damper eliminates this but it's an expensive solution.
Check for corrosion on the link pipe between the two exhausts, it's in an area that collects crud and they're expensive to replace.
The only other problems I've had was the battery dying after four years (but not a huge surprise as batteries have a finite life).
The exhaust pipe from the rear cylinder cracking. Not a common problem but my dealer said I wasn't the only one they had seen, an easy fix but not exactly cheap!
The seals in the clutch master cylinder failed, a cheap and easy (if fiddly) thing you can fix yourself.

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