Now the question was about a suggestion to have a balance between best designs considering a friendly URL, Ajax, and SEO. It was implied about some contradictory indications. With the discussion passing on to friendly URLs are great if for no reason than log analysis, however, friendly URLs are supposedly better for SEO also (besides all
the other stuff for SEO).
Suppose if you would like to start moving over to AJAX for CMS-related, stuff, such as loading a news article when the user clicks on a headline, and stil make the site really search engine friendly.
The added benefit to backloading your ajaxification is that regardless of js enablement, the user could right click your link and open in new tab or window or even bookmark it and it’s still a plain link that will open normally. (Mark Armendariz at NYPHP).
The overall suggestion is to use prototype.js, and some implementation to use asynchronous fetch.