I have absolutely noticed that. Since it became free I flew them... five times? But I have also noticed some consistent areas where service was slow no matter what. Seems like too many people wanted to download stuff or watch videos.
Was reading
http://www.gadling.com/2009/12/07/ai...+%28Gadling%29 the other day, and if true, then they can really use some upgrades to that in the future before it becomes completely unusable....