This unit features a 'hard' power button, meaning that if anyone in your house (family, friends, guests) turns this off via physical power switch, if you then try to use your remote, or smartphone to power this back on, the device won't turn on. You'd need to stand up and walk to the device to turn it on every time this happens.
Isn't this a minor issue? why complain? Because Yamaha already fixed this in their AV Home Theater receivers, they feature a 'soft' power button, meaning that if you send an Airplay stream, or MusicCast, or you simply just want to turn the device on, it will work 100%. But with r-N602 it won't work, for some mystical reason Yamaha chose to put a hard button instead of soft.
The issue is further amplified if one tries to use this like Sonos, to stream to the entire household. Suppose that you have multiple audio devices throughout your home, when you send airplay audio or MusicCast to them, you'd expect them to turn on automatically and start playing music in sync.
With R-N602 you won't be able to, because if someone turns this off via physical button, the audio stream won't work and you'd have to manually go to each device in your house that didn't turn on.
This may or may not be an issue for someone, depending on their usage and needs, but the bottom line is Yamaha could have avoided this issue by using the same 'soft' button that they use in their home theater receivers.
Another issue to consider is that Net Radio, while it's quite awesome due to the plethora of music stations, won't remember which station you last played. So every time you turn this on, you'd need to use the tiny screen and buttons to navigate to your station which can get annoying.
Another issue is the iOS app. It won't let you add Net radio favorites easily, it's extremely difficult requiring you to go online and do some setup. The interface is poorly designed and slow.
One last thing to consider, the front panel is beautiful aluminum, but picks finger prints and smudges like crazy and it's almost impossible to clean.
It's unfortunate these minor issues seem trivial and should be easy for Yamaha to fix, but overall they diminish from the excellence that Yamaha stands for, and for the price of $600 for a stereo receiver I expect no less.
I'm currently using Yamaha's RX-V479 as an alternative, note that this is meant as a home theater receiver, but it does work quite well as a stereo receiver for my needs. It features the soft power button so whenever I use remote/smartphone or send an airplay audio, it'll turn on 100% of the time beautifully, Net radio remembers the last station, and the unit doesn't pick up fingerprints and smudges as easily. The only caveat is that it requires a TV for setup, but once the setup is done, I detach the TV, and use it perfectly fine as a stereo receiver. Until Yamaha fixes the pending flaws, this will be my workaround.