Man, I'm pretty disappointed that the BT issues are still present today. I was going to purchase this for it's bluetooth connectivity for browsing and photo editing...But now, not too sure about it.
I use mine with the Logitech Unifying Receiver and it works beautifully - I'd say don't let any bluetooth issue stop you from purchasing the MX Master, it's the best mouse I've ever used, love it. The only thing I can't do is wake my Mac with a click - big deal