Sgt_Kickaxe - 4:41 am on Mar 2, 2012 (gmt 0)
There is a lot of copy-cat mentality going on right now amongst my group of competitors. When one site does something and holds top rankings the others aren't far behind in doing the same thing. Images instead of text for titles in H tags everywhere but on the actual article page for example(something about not duplicating a page title anywhere but on the actual page).
As always do some a/b testing and start small, perhaps with a few pages at a time, and give sufficient time for the changes to fully propagate(2 weeks+ minimum) before assuming anything. Also, do not make too many different changes to existing pages all at once if you need to measure the results accurately.
You know, I can't remember the last time I saw ANY on-page SEO change result in a major traffic jump at the page level(unless something was blatantly wrong to begin with). It's seemingly more important to focus on off-page factors these days, on things a webmaster usually cannot control, such as being spoken of on an industry juggernaut site.
Usefulness of page and off page signs of trust are king right now.