So I bought a (singular) Play:3 for the kitchen, and besides it being the easiest thing to set up ever (full report to come), when I try to play anything from my iTunes library (which is on my iMac, connected to the network wirelessly), I get "network connection speed insufficient to maintain playback buffer".
A google search suggests that having a library on a wirelessly-connected PC "is not supported". Whilst my first reaction was "wtf?", how does everybody have theirs set up? Are you all using a wired PC or NAS (which I can't believe), or do I just have poor network connectivity (which is quite possible)?