That was an eye opener, and head scratcher too me too!
You probably know everybody has their own opinion on oil (As well as tires.)
Here's mine . . . I have tried that expensive Amsoil oil after going years with the stock stuff that came from Honda.
I didn't like the actual mechanical sound that came from the engine with the Amsoil, it seemed way too noisy, this was supposed to be a Honda - not a Harley Sportster. After giving Amsoil one shot, I went back to the stock stuff and haven't given it much thought since, it's back to smooth and I figure if Honda built it to run with this "Who am I to argue?"
I ran a K&N filter a few times, and then also went back to the stock filter, it's a little cheaper and as above, if Honda built it to run with this "Who am I to argue?"
I usually change my oil once a year, which varies as the season and what my life allows, but I'm still leaning more towards 3,000 miles between changes, but I'm really not too concerned if it were to sneak up on 5,000 miles which hasn't happened yet.
Our bikes aren't big on horsepower, so what I want in an oil is dependability, that's why stock is fine with me. Some members will tell ya that they use Shell Rotella, or Royal Purple or what have you, the main thing is that you use quality motorcycle oil of the correct weight and change it often.
Truth be told, our beautiful, low RPM, water cooled engines would probably run fine on any decent motorcycle oil, so use whatever kind that makes you sleep better at night.
What the hell is that sound?