After about a week's worth of additional use, I've concluded that the Core Control app on iOS 7 is below par. Controls disappear, focus disappears, search function doesn't work. Not occasionally. All the time (Three times already just while typing this post).
I've also experienced some odd behavior with the Rhapsody integration that I haven't seen before: core control thinks a track is in my library (I can remove it via the rhapsody menus) but I can't find it in my library. More experimentation is needed to see whether this is related to certain albums only or a more general problem. I doubt this is caused by the iOS 7 upgrade, but I've seen stranger things in my days.
I also think it's time to have proper Retina display support. This display was introduced in March 2012 if I'm not mistaken. And yet the UI elements in the app appear pixelated 1.5 years later. The last update to Core Control was released May 18, 2012.
Sure, QNAP support (though only relevant for windows users?), decked out Range Rovers and McLarens, Explorer and Director DACs are all nice developments. But, the reason I invested in Meridian �besides the sound� is that Meridian was at the forefront of the computer audio/streaming/digital music evolution with its user experience and integration. I want to believe they are still leading and have great things cooking in the lab. If so, please hurry up, because I'm losing faith.