MBP 2015 model here, on latest OS X El Capitan. We have two other Mid 2012 MBAs. When my MBP comes out of sleep, it is very slow to reconnect to the internet. The WiFi indicator shows that it is connected, but when I open the cover of the computer, it just sits for over a minute before the internet becomes available. To eliminate the router as the issue, I just purchased a new Airport Extreme. Prior to this, I was using a Netgear Nighthawk. Both of the MBAs are also on OS X El Capitan, and neither of them has any problems connecting. I have tried everything that I can find on the internet to fix this, short of a clean install of the OS. I've spent many hours on the forums, but nothing's worked. Has anyone had this problem and managed to fix it? I'm getting ready to just take it in to the Apple store.