Found this thread after ordering a TX-NR616 from Amazon, doh! I Had an older 700 series (pre-HDMI) that worked flawlessly for 6-8 years. I needed to update to a receiver with HDMI and have always like Onkyo, so I went with a 616. Set up was fine and everything worked for about two weeks. Then my ethernet port basically stopped working. Since it was still in the return window, Amazon suggested a firmware update, however, I could never get a USB drive to be recognized by the receiver. I tried three different working thumb drives loaded only with the firmware per instructions with no success.
Amazon then sent me a replacement and the ethernet and USB was non-functioning on that unit as well. I ended up sending that receiver back and getting a Yamaha V673 instead (plus I added the 3yr warranty this time). Set up was quick and easy. I plugged the ethernet in to the Yamaha using same cable and same mini-switch port and had online access right away. So far, so good.
Another benefit is that the Yamaha has built in airplay, so I'm sending back my Apple TV that I got specifically for audio streaming to the receiver.
The IOS remotes between both receivers are similar and the price point is similar. I am bummed about the Onkyo, but I don't think I'll be getting another. Too bad, I've always preferred the brand, but it really sounds like they've produced a lemon with this series.
Bummer story...still using my 616 every day since may 2013 for mid level home theatre system and simultaneously whole house audio. Funny, I'm shopping for a four wheeler for the lake house and the biggest selling/most popular/biggest value brand is just like Onkyo. Some get a good one and it works as intended and the value is realized and others are getting a lot of nickel and diming. Sometimes it is just a crap shoot. The other brands of four wheelers are substantially more money class for class for less features, less horsepower, less innovation, less of everything except they have a better reliability reputation but of course sell a fraction of what the popular one sell.