And bodies. Had to move my laptop dock to the other side of my desk when I switched headphones from a pair that had the transmitter in the left ear to the right.

Yeah that is perhaps the most problematic aspect of Bluetooth. The radio interface is designed with the presumption of the signal bouncing off nearby surfaces. Thus it is sensitive to line of sight issues.

Mind you, i have also been able to connect to a USB dongle through solid wood walls, so mileage may vary.

Never mind that you can get two classes of radios, on top of the LE stuff. With each class having different transmission strengths.

Sacks of water will do that :)

Wet dogs can play havoc with wireless.

Both use the 2.4 ghz spectrum, so that makes sense - especially for bad microwaves. I had an old microwave that completely tanked my 2.4 ghz Wifi back in the days (very poorly shielded).

I still do. The ability to stream music in my kitchen is the reason I bought a 5GHz router.

Bluetooth is using the very same microwaves (much like wifi), so yes.