The service interval for the Wing and Traxxion is 20,000 miles. Not sure how that compares to stock but it doesn't need a lot of attention. Just ride and enjoy.
All Balls. Yes. yes. and Yes. Steering and feel is so much better! No more headshake which a lot of the GoldWing Wobble and can be attributed too. So much smoother and easier at low speeds when you actually have to turn the bars. I also did the Fork Brace and the Triple Tree's. Awesome. The Triple Trees take the flex out of the front end and the fork brace keeps the forks from flexing around.
I now have zero headshake, no decal wobble, longer tire life, better ride, better handling, more ground clearance and overall more pleasure riding. Here are a few pics to show the difference:
Stock ball bearings (just in a race and loose) vs All Balls Conical Bearings, big difference (stock is left if your curious):
Triple Trees = Flex no more
Even the rear shock just looks cool and you don't even see it but the sock keeps crap out of it and the adjuster:
Hope that helps...