Pioneer AppRadio 4 vs 4200 NEX
Installed a few in customers vehicles but haven't messed with it much myself. Putting one in my Land Cruiser this weekend so I'll let you know how that goes after I play with it enough.
Edit: initial impressions are good though as an essentially CarPlay dedicated radio (I know not entirely but that is front and center with the unit really). Only other direct competitor is the Alpine ILX which does CarPlay in a slightly cleaner fashion, and I mean just slightly. But the Alpine doesn't offer Bluetooth audio so in order to play your music you always have to be plugged in. Which is the main reason I'm doing the Pioneer.