Fishbein said:
I assume you can't notice the difference in the ride, just good lubrication...?
If your oil is really dirty then a change to any quality synthetic will probably give you a bit of a noticeable improvement. The bike may run a bit quieter and your shifting may be a bit smoother. If you read the test results you'll see that Mobil 1 4T is an excellent oil and would certainly yield the same improvements after a change.
I like Amsoil. I like the fact that its an American made product, and I like the research that is behind their products. That said, its only my opinion and I don't mean to imply that its any better than anyone else.
If you decide you'd like to order some Amsoil products let me know and I'll send you a link to my website. Lots more info there, even if you don't want to order anything. I don't want to post a link since that could be construed as advertising.