Something that's interesting about this data is that it measures speed end-to-end. So if you are an ISP that gives out flaky WiFi routers, your score will be lower not because of any limit between YouTube and the ISP or the ISP and the CPE, but because of that "last meter"* between the access point and laptop.
Is FiOS still giving out those terrible Actiontec routers? If so, maybe this will get them to fix that.
I still remember switching from them to Comcast to what should have been a far better connection (over 2x download and maybe 8x upload) and thinking it was crap... until I turned off the access point in the Actiontec and started using my old AP again.
* A new term I'm coining for this :)