I've got a Mid 2014 model Macbook Pro Retina that just will not quit with its Wi-Fi issues. Its been happening since a few months after I bought it. The Wi-Fi just grinds to a halt. No error messages or anything, it just basically stops loading webpages. If I open a link to a youtube video, sometimes it will load fine and at full speed, other times it will load the page but the video will load at about 1 second per 30 seconds of actual time, more times it just display a white page on chrome with a loading symbol on the tab and this can last for 10+ minutes. Sometimes webpages will fail to load and give an error about no DNS. I forget what it says. I see it so much I tend to just ignore it and haven't read it in months. Sometimes, this issue might not present itself for weeks, then all of a sudden its happening 24/7. It took me just shy of 7 minutes to go from the Macbook Pro forum on here to the Create Thread page, despite having a 40Mbps internet connection. Sometimes I'll test it with speedtest and I'll be getting ~0.5Mbps. Immediately after testing, my PC will get a solid 38Mbps over Wi-Fi or Ethernet. Same goes with my phone. It just seems to be my Macbook that gets slow over Wi-Fi. When the issue is happening, I've tried pinging google.com with the Network Utility and more often than not, I get really high Ping on some of the packets and I usually get a lot of packet loss. If the issue isn't there, I get very low ping and zero packet loss. I've been updated it every time there has been an update right until the release of OS Sierra (Still on El Capitan out of fear of things getting worse). No update has made any difference. I've tried every solution from every article from the first 10 pages of google and I've tried every youtube video under the sun. I'm really at my wits end. Its driving me insane. Nothing would bring me more satisfaction at the time of writing this than to take my Macbook outside, put it under the wheel of my car and run it over a thousand times before hanging it off a tree and shooting it a dozen times with a shotgun. I'm tired of it. I just want it to work.