I agree; I fly with decent panel kit also.
I was asking the Q from the POV of a pilot who has nothing at all. IMHO, a bluetooth GPS receiver stuck somewhere high with a good sky view, and some kind of computer running a decent big VFR chart, is a whole lot better than map reading, or radio nav with the typical dodgy rental spamcan nav gear.
Bluetooth is indeed "a technology with a great future"
but if one sets it up and never messes with it (at either end) it should keep working (under windoze, pocket/pc is something else......). And if the connection fails, it is generally obvious on the display device.
I've been flying around with a BT GPS and a tablet computer for about 6 years, and I would happily use it as my only nav method, VFR UK and Europe. I went all the way to Crete with that kit, and sure as hell I was not doing any map reading, especially when VMC on top