I'm amused at the hysteria over the loss of the album art in the lower left window, in that it has somehow crippled the user's comprehension and ability to remember the name of artists, albums, songs etc. I find this thread entertaining and stimulating - so please keep it going 🙂
In response to the question about my library size and what device I use to manage - in reality I have about 6K of songs and I use multiple devices to manage playlists depending on what device I am using. I have a Mac Mini as a central media server, Apple TV, MacBook Pro, iMac, a Dell XPS All-In-One and a couple iPads. My wife has an iPhone 5 and I have an iPod Classic and a Samsung Note II. My two daughters have Macbooks, the elder has a Pro and the younger one has the Air and an Amazon Kindle. Our whole family is always buying music on iTunes and me the same - we have CD's too, that we import. We have iTunes Match. I love Apple, but I also like Microsoft and I like Android. I don't have any allegiance with a particular supplier of technology.
I don't really do that much managing, because when I import music, I make sure it's correct, so no further tweaking of the metadata is necessary. So I don't find myself continuously managing the music, because there is nothing to manage, other than playlists. I'm not an improvisational "house music" DJ either, so usually when we have parties, we create the playlists beforehand. Album artwork is certainly enjoyable to view, but I don't feel that ability has been lost with the new version of iTunes. I also consider myself to be flexible, adaptable and open to new ideas and ways of thinking. I welcome changes in software, because I know there are people that are smarter than me designing this stuff - and I enjoy their creativity.