No, I meant AAC. The XM3s do not seem to negotiate AAC over BT on OSX. They fall back to SBC and obviously sound bad. AAC would be a step up, but AptX HD or LDAC would be ideal. They work fine in my case on both iPhone and Android.

So as I was saying I'm tempted to move back to Linux for my work laptop for LDAC over BT support as well as other reasons of course.