21,000 miles on my '04 FJR, have used one gallon of the Rotella T 5W-40 full synthetic motor oil plus 8 ounces of STP Oil Treatment and the Mobil 1 high efficiency oil filter since the 1100 mile point, oil and filter changed every 5000 miles. Engine is quiet, no ticking, absolutely zero clutch slippage even under near full throttle upshifts, shifts buttery smooth, no problems whatsoever. Not a money issue at all for me, I just believe the oil combo works superbly in the FJR and is superior lubrication to the dino Yamaha stuff. I use the Rotella T synthetic in all three of my cars, my diesel truck, GL1200, my Nighthawk 700S and the two GSXR's that my son and I ride. Not a single problem in any of the vehicles or bikes. 167,000 miles on the GL1200, all on synthetic motor oils. Never had a clutch slip on any of the bikes.
Hey, do whatever you're comfortable with. I'm not trying to convert anyone.
Lee in the Mountains of Northern California B)