I've probably used about 3 different wireless bluetooth audio devices and had varying levels of quality, some of them approach the analog audio out but none have been better:
- Bluetooth hands-free headset about 7 years ago. Phone calls were OK, PC audio was a shockingly bad.
- Bluetooth sports headphones, before A2DP. Noticable compression and distortion
- UE Boom bluetooth speaker. Uses A2DP I assume, quality is OK but hard to tell on such a limited speaker. Fine for ambience.
- JVC Bluetooth car head unit. Uses A2DP, and since the speakers/amp are better i can hear some of the compression. Like a low end MP3 I guess, noticeably worse than the high bitrate MP3's stored on the phone. It's a reasonable compromise for convenience though.
So yes, things are improving, but it's not great yet.