The Classic and Reference forked arms are equipped with anti-skate and azimuth on the fly adjustability. Using the Fosgate Fozgometer and the Clearaudio azimuth test record its simple to get a reasonably accurate azimuth setting.
In my experience the fly in the ointment is the irregularity in the thickness of the vinyl in the label area and weather or not the clamp is all the way down. This can affect the Fozgometer reading slightly. Audibly, I'm unable to hear the difference.
Another observation. I've found changing the tonearm cup fluid with 100,000 cst polydimethylsiloxane fluid from Turntable Basics at least yearly has had a noticeably audible affect. Two 10ml syringes should be enough for the job if the paddle is properly located.
I have no experience with the Koetsu. I've had Benz Micro Wood Lo and the 10.7 gram Ruby Z, compliance 15, tracking at 1.9 grams.
IMO the biggest improvement in LP playback is ultrasonic record cleaning.