Exactly as Michael says.
Some nights when everybody in our neighborhood is watching NetFlix, it is simply impossible to get a decent connection, and flashes (and their accompanying low bitrate blur) are constant -- even as we can still get 9Mbps stable on Vudu. One thing we do is restart the movie, which often will give us a better NetFlix server. We give it 1-2 minutes, and if it doesn't settle at a high bitrate within that time, we know it's not gonna get better and restart it. Sometimes it takes 10 tries or more, but once we get a good server, it usually goes straight to max bitrate (high PQ) and stays there for the rest of the movie. When we get a good connection we DON'T pause for potty runs or popcorn, or we lose that good connection.
My 110 only has wired, but from my experience with a Vizio player before getting my Panny, WiFi definitely increases the risk of NetFlix bitrate fluctuations. Of course, if you have a super connection, you live right next to a NetFlix data center, and none of your neighbors use NetFlix, even poor WiFi might be good enough. But it's absolutely an additional weakness in the chain.