CDN can be your site's lifesaver in pageload if you have a lot of images too! it can be how you have it set up too.
we have created 4 sub-domains on our site that are all connected through our MaxCDN Pull Zone. By having 4 subs, it breaks each one up for images, js & css so they're pulling from those areas rather than just one spot.
When it comes to measuring page speed, you'll usually wind up with different scores on each place you test.