We don't spend a whole lot of time focusing on home theater receivers 'round these parts, but we do like AirPlay, and we're especially fond of audio devices that boast compatibility with the iOS wireless streaming tool out of the box. Yamaha's RX-V573 and RX-V473 are two of the latest mid-range audio mixers to ship with AirPlay integration -- a feature lacking from the company's past offerings -- along with compatibility with the AV Controller app, available for iOS, Android and the Kindle Fire. There's also a nifty 4K video pass-through feature, which won't do you much good at pres
