They have improved the stream quality, but mine freezes all the time for a split second.Probably 10 times in a game. So i purchased a new wired box, i had exactly the same problem.My other box does this as well despite a 72 mb connection. It never used to freeze but it was like watching a dodgy stream, except i was paying for. Yes i have rebooted everything!
I've had sky sports on Now tv for 18 months now, its the best quality it has ever been but i just put up with the 1 second freeze, i have also changed my wifi channel on my router.