I just installed it on one of my test Pi's I have here. Pretty damn easy, but I forgot the Pi only has a 100 mb interface. So if you have over 100mbps internet, you'll have an issue. I think I will install this one a few of my content filtering servers I have at work.
Pi:
Desktop:
One of my virtual servers (fast nets)::w00t:
EDIT: If you have a bandwidth cap, don't configure the cron job to go too often. These speedtests use a good bit of data.