RSSI imprecision is just the nature of the BTLE. Bluetooth signals tend to bounce around in room that is full of objects, heavy metal blocks signals, etc.

To solve the problem, this can be accomplished by collecting an array of RSSIs and averaging them to get a more accurate result over time. Being said, for time sensitive use cases, it's pretty challenging to use iBeacons. Nevertheless, iBeacons has a lot of potentials.

I also think iBeacon will eventually dominate the proximity detection market. Here are 3 reasons: 1. Apple has a dominant smartphone market influence. 2. Apple released the iBeacon spec into the wild, and there will be more companies manufacturing iBeacons like estimote. 3. Google's BLE API is not that mature yet.