I'm not sure, I'm no longer working on products that use BlueTooth. I know that BT pairing has gotten easier and easier over time (improvements to the spec), but the real important parts are the BT stacks and BT chip firmware. From what I understand working with BT Engineers, the best BT stack was from Stonestreet One, who was recently bought up by Qualcomm. If someone had bought them up and open sourced their code, the world of BT would be a much better place right now.