"The offline playback stuff continues to be pretty clunky to set up. If I know I am going on a road trip and will be driving out of range, actually adding that music to the device is a huge pain, and often the easiest way is just to leave the device playing music for days and let it build up a cache. Horrible."
It's not obvious but the way to do this is to "pin" (aka mark as keeping for offline) playlists on the device. Create a few travel playlists, pin them on the device, put the device on wifi or change the data settings in the app, go to the web client and mass drag and drop songs onto the travel playlists. I manage about 6 GB worth of offline music this way and it works decently. Once in a while you have to go into settings and tap "Refresh Music" to get it to recognize a new playlist but I maybe do that once a month.
This is my favorite feature of the service (Spotify has this, as well). The best part is you can pin a playlist and it auto-updates when you add songs. When I'm going out of the country I'll create a 'Trip to XX' playlist, pin it, and then over the days/weeks leading up to the trip add things to it. The app auto-downloads as you do so.
It also does it across devices! I have a crappy old smartphone w/o a sim card that I use for running, and have a running playlist pinned to it.
I can be listening at work, add a song to the playlist, and then back at home the device automatically downloads the new song over wifi for when I go running. (I'm sure spotify does this too)
It's not obvious but the way to do this is to "pin" (aka mark as keeping for offline) playlists on the device. Create a few travel playlists, pin them on the device, put the device on wifi or change the data settings in the app, go to the web client and mass drag and drop songs onto the travel playlists. I manage about 6 GB worth of offline music this way and it works decently. Once in a while you have to go into settings and tap "Refresh Music" to get it to recognize a new playlist but I maybe do that once a month.