RSSI imprecision inherent in BTLE is exactly the point I wanted to make. The marketing around BTLE focuses on "micro locations" but I feel that that's misleading given that in the real world, you cannot reliably get even approximate precision (let's say 5 feet) let alone micro precision. Human walking speed alone is enough to blow the whole "micro" concept out of the water.

Another sticking point for me is the battery life. The transmitters are touted as low energy, which they are, being able to transmit for 2 years on a watch coin battery is amazing. However, a transmitter is useless without a receiver (did the tree really fall...) and the receiver is going to be anything but low energy if has to continually scan and compare surrounding signals. Granted, my demo receiver app was as unoptimized as you can get (one day of coding plus I am not even an iOS developer) but at the same time, it didn't do much but look for signal, and it was chomping through battery at an alarming rate. It was ok for a 5 minute demo but I can't imagine real users would put up with this for long.

Given these two limitations, I have a hard time imagining wide adoption.