We've not changed anything, however Google have rolled out a minor update to the drivers on the Chromecast with Google TV which has boosted performance slightly. They do acknowledge that the boost is minimal and they still have a long way to go - it's still under active investigation.
Sorry to hear of your poor performance even at 1080p
@Simejack. I can only recommend at this point that you select the regular channel to play (and reject the Ultimate prompt), rather than selecting the event on the home screen. This will give you 1080p SDR, which works well.
