Question About Jungles after 6.9 patch

So this question regards the removal of devourer and how it affects the champions Jax, Xin Zhao, and Udyr. I know that recently quite a few summoners have told me that the Runglaive is a better jungler item on Udyr, and Jax also has better AP scaling simply because more of his abilities scale with ap than ad.

Is it more beneficial to simply get the AP jungle item and perhaps get a Rageblade? What would the rest of such a build look like? The new AS jungle item seems very underwhelming...