Very cool, but I don't see file size as a significant factor when making a decision about what library to use. With SPDY, fast pipes & 4G, minification etc, worrying about super tiny file sizes is becoming a legacy issue.
File size is a very real measure that needs to be monitored. Naturally, if you're building a basic website then it's hard to make your pages too bloated, but I've had numerous interview candidates throw over CV's with basic one page portfolio sites that hit the 15MB mark, and these people often don't get the job.
Hell, even Hacker News isn't as fast as I'd like it to be on my connection.
Now, I don't even think the overall quality of internet connections is that great in the US and I'd say most European countries do a better job overall (less disparities inside individual countries, not among all European countries).
And finally: http://www.techpark.net/2010/04/15/broadband-internet-speeds...
But yes, file size must still be considered. 3G, bad reception, congestion, spotty wi-fi and loading speed (spdy isn't that much faster) are very real concerns.