Dunno if this holds up for others, but Bing is substantially faster than Google's homepage to load, even with all of the crazy graphics... Impressive.
What really matters in practice is "time to first interaction" which is when the user thinks your site is useful. Next up on my feature list is having a button to indicate which pages seemed to load faster to you. The idea is you can send a link out to your friends and get their impressions, which is more valuable than the numbers you can get with an automated tool. :)