On Mac there are ways to change the bitpool values to change the way the SBC Codec negociates audio quality with your bluetooth headphones. (See this question for more details)
By default though, even without changing the bitpool manually, my Jaybird Bluebuds X sound great on my Mac. I can't get the same results on my Android Nexus 4 or Windows 7 (Asus USB-BT21). I've searched google many times and I can't find any results to adjusting the bitpool of the SBC codec on Windows (or anything recent for android, for that matter).
I've ruled out BT hardware as well - I get the same good results on a Macbook Pro 2014 as I do on a Mac Mini 2009. I've even tried using the Asus BT21 adapter on the Mac, and the results were good as well.
Is it just expected that BT audio isn't as good in Windows drivers?