How reliable is the FZ8 at high miles?

Because many Yamaha FZ8s are now approaching higher mileage, the long term reliability of the bike is becoming more and more of an interest to current and potential owners. This is a contentious topic as people discuss how the FZ8 stands up over time to its competitors and what sort of issues, if any, seem to pop up as the odometer ticks over. Riders who have clocked high mileage on FZ8s share their experiences and maintenance requirements, as well as wear items and any surprises they've encountered. The conversation often centers around whether (and how often) to service the machine, how good Yamaha's engineering truly is and how much a rider's style and environmental factors might affect longevity. Some claim that the relatively simple design of the FZ8 helps keep it durable, whilst others point to potential weak points owners should be aware of. For those thinking about a used FZ8, or those wondering how many miles their current bike has left, this discussion is for you.