nothing like a good oil thread to the interwebz alive
I got nothing to add but my opinion
Amsoil 10w40 is good oil
that's what I have used for years and years
that's what I will continue to use
for years and years
and I am not smarter than a Honda engineer
I just ride bikes
a lot

I use Honda oil and filters on my ST and CB and Yamaha oil and filters on our Majesty's. No particular reason. I buy the filters several at a time. Oil in gallon jugs. My local dealer gives me a small discount, and I like showing him as long as he's good to me, I'll support him as much as I can. Some things, like accessories, he's ridiculous on, and I just can't afford to buy from him, but I can afford the oil and filters. we both benefit that way.
Last week I changed the oil and the filter on my bike and I was very surprised how thin the hot oil was.I came back from a 90 mile ride in 85 degree weather but not much town traffic.I have done hundreds of oil changes in my 45 years of riding but rarely seen the hot oil that thin.I therefore used semi syntecnic 10-40 from Honda and the Honda filter (same as my CB1000 filters)I always use the Honda oil and Honda filters.Some one once said that Honda is not in the oil business,I said yes but they are in the warranty business !!!
I used Castrol Synthetic motorcycle oil in 10W40 on my second oil change today with a Wix filter. I have the number in the garage if anyone wants it.
Castrol Power 1 4T 10W30 Part Syn Motorcycle Oil CAS-2279-7009-4 - 4 Litre
Castrol code : 2279-7176
That's what they had in the Honda dealer. Sent from Honda they said.
Don't kid yourselves. Oil is not made by Honda.