Received update yesterday on both my Nexus 5 and Nexus 7 2012. Seems to be much smoother but wifi although it shows as being connected drops off intermittently. I'll be in an app like eBay and when I do a search it will periodically say "network connection is lost. try again." After several attempts, the search finishes and displays the results. The lost connection happens in several other apps as well like Messenger (Facebook), Hangouts, Chrome, Google Play...etc. Basically any app that requires a network/internet connection. I've tried reinstalling and factory reset - the problem still continues. Everything was working fine prior to the 5.1 update. Seems for everyone else the update has fixed their wifi issue problems meanwhile mine is not anymore. Note: the problem exists only on my Nexus 5 and not on my Nexus 7 2012 which has no issues so far from the 5.1 update.