I've noticed a big slowdown in PV EC2. One machine used to be fine running apache and mysql. I had to add a 2nd cpu and split the mysql off onto a different instance to keep load to manageable levels.
Hydra/Gamepedia got hit by the patch on its Elasticache instances around the same time. Redis is used heavily on its caching infrastructure and the web nodes starting thrashing due to the sudden performance loss.(Until the resources were increased.)