I am noticing that PageSpeed numbers are different (lower) in Google Webmaster Central than they are in Google Analytics (higher). Does anyone else notice the same? If so why do the numbers differ if it is coming from the same source?
Analytics sums up the average page speed for your site. This means that "freak" occurrences (page loading for 10 min for a specific user or loading really fast for some one who sits very close to the server) will dramatics change the final score.
WMT tries to benchmark your site and give you the "bigger picture".
I would trust it more.
If you have a speed issues I would also recommend trying out CDN cloud services <snip> We saw up to 40% improvement due to CDN and our dynamic caching features.
[edited by: incrediBILL at 9:41 am (utc) on May 24, 2012] [edit reason] removed specifics [/edit]
Note that WMT gives you a hint regarding the accuracy (the number of data points) in the paragraph above the performance graph.