In my previous post about x264 I'd promised some side by side comparisons and hadn't delivered as yet (sorry, I've been busy). Well, while i'm here at BAVC, encoded some content for one of the groups (Power Poetry) of their trailer. We compared that to the H.264 version they had just done and the results were quite different. The basic video settings were the same in each (data rate and key frames were set to automatic) but in the x264 side, I used the same advanced settings from the previous post.
When I get some free time, i'll post a few more tests and some actual movies, but I thought i'd share these to show there is definitely some benefit to testing out the x264 plugin.