only problem i see is that it is against a lot of advertising companies TOS to have an add on a search page, and on pages with no content like usercp etc.
i like it how it is honestly, when im surfing i like the thread view to be full width for easier reading, if i want to quick go to my fav box i just click back. also just in case it should be mentioned that the new post dropdown in the navbar has the new fav posts search.