I had the closest shave I've experienced whilst using the Zaon XRX - 200ft separation with a pair of F16's (according to the air-force jock in the lead ship); fortunately, he took evasive action which saved all our bacon but there was no indication of closing traffic on my equipment that particular day. I've also encountered spurious alerts triggered by my own Txpdr however it is generally a good bit of kit when used in support of a comprehensive lookout.