1. No audio line-in! It's a $300 speaker, it sounds great...sometimes I'd like to be able to just plug something into it. If you have a record player, you have to have a separate set of speakers for it, because this thing won't work.
2. No EQ. Apple claims their room-sensing tech will pick the best EQ for your room/the music, but for my personal preference it's always too bassy-sounding (also, I live in an apartment, I don't want to disturb my downstairs neighbors with the bass). Apple added a limited "bass-reducer" mode, but I want more control.
3. Siri tries (and frequently fails) to identify me and my wife by our voice, and then won't do things (like turn off the music, find our iPhone, etc.) because she can't figure out who we are. Every time Siri refuses to obey my wife, and then does something when I make the same request, it ratchets up the marital tension a notch.
I should probably get rid of the thing, but it's actually convenient when it works, the kids use it constantly to play music, and I assume (naively?) that it has a better privacy stance than the competing Google/Amazon products.