[gman99]

>all Skype calls automatically revert to HFP (extremely bad quality)

While it's true that audio quality over HFP is a lot worse than A2DP, note that A2DP is designed for cases where latency is not an issue, you want stereo audio, and there is no microphone audio to carry the other way. (i.e., designed to listen to music)

If you want low latency mono-audio to the headset + microphone audio back to the host, there is no choice except to use HFP.

Note that if your headset (and your host device) supports HFP1.6, then it should support wideband speech/HD voice and the difference should not be so drastic.

[voltagex_]

The problem is finding both the host (dongle/chipset/card) and client (headphone/speakerphone/headset) that support the correct versions. Most of the time the information isn't listed anywhere, and Windows certainly doesn't expose it by default.