chrisv1963 - 11:50 am on Mar 28, 2011 (gmt 0)

We're seeing significant improvements too. Unfortunately we just rolled out some major optimisation changes, so as per usual it's difficult to tell what's caused what, although the improvement I've seen is far greater than I'd expect from the changes we've made - which means there might be something else at play here - Panda? What's weird is that our US traffic was hit hard by the Panda update. If this really is Panda in the UK, then it would appear that we're actually doing much better.

Maybe Panda UK is taking the changes that have been made to sites into account and Panda US isn't doing that yet.