I've got 27000 km's on my fuel injected, no issues yet.
Thinking about doing my valves this summer.
I did my old inline 4 cylinder Suzuki motorcycle once. Easy peasy
5 minutes to get the valve cover out of the way, and everything was right there.
This dam thing, likely 4 hours to get the head off!
I won't be buying Yamaha again, as it's just way to complicated.