Decided to revive this old thread rather than make yet another Slacker thread.
I've been pretty happy with Slacker over all, and have even started listening to it at work through my phone.
They have these amusing countdown lists ("66 songs that changed everything", "101 greatest new wave songs", "50 most banned songs of 2013" etc)
And when I listen to these lists on my phone there's commentary that comes up sometimes to talk about the song and why it was picked.
In the car, however, I don't get the commentary, and it's too bad because it's interesting to hear why certain songs get picked.
It may be due to the account type (but on my phone I'm just using the free account with ads) or it may be Tesla's implementation.
I'll try and send a note to ownership at some point.