I've noticed that many times a web site will look as if it's been fully loaded but the progress bar is still showing there's work to be done (probably loading ads from a different server, or loading images at the very bottom of a very large page like Planet GNOME). This takes an extra second or two in a lot of cases, where the web site is correctly displayed but the progress bar doesn't indicate it as loaded yet.

I think this makes it seem like web sites are taking longer to load than they actually are - users should start reading a page as soon as it appears to them that it's available, but the very high visibility of the progress bar might encourage them to wait a little longer.

An interesting experiment is to compare Epiphany with other browsers side by side. While I felt that it was generally slower, in comparison it's actually just as fast or faster in most cases. It's just the progress bar making it seem like it's taking significantly longer to load pages.