I intentionally made the topic subject sound scary, because I think this is a safety of flight issue. The iFly audio alerts are terrible to the point of being dangerous. I am using an iFly 740b. Problem Example 1:
Yesterday I was flying around the local airspace, and I saw two ADS-B targets flying in formation about eight miles away, heading in my general direction. No problem, I go about my business. A few minutes later I get a single "ping" alert, and look down at the display. I was startled to see the pair of aircraft are now 1nm away, within 500ft altitude. I look to their position and spot them doing a hard turn into me (they were doing formation aerobatics), *very* close. They level out and pass overhead, within 1000ft of my aircraft. All I ever got was that single ping at 1nm. No other audio alerts. The traffic alert box was up on the screen.
Out of curiosity, The rest of the flight I intentionally flew close to other ADS-B targets to see when I got alerts. I twice got alerts for aircraft that were 4-6 miles away and behind me, no factor. I *never* got any further audio alerts for aircraft that got within two miles, even after rebooting the 740b. I have seen similar behavior on several flights previously.
My alert thresholds are set to 7nm and within 5000ft of my aircraft. A single ping at 1nm within 500ft with these settings is NOT acceptable, and is dangerous. The whole point of ADS-B traffic is to warn the pilot so they can keep their eyes outside the cockpit and fly the airplane. Having to watch the display like a hawk because I can't trust the audio alerts is not what I had in mind.
Problem Example 2:
Obstacle alerts are extremely inconsistent. Sometimes I get alerts to obstacles that are 6nm away, sometimes I get none until I'm right on top of them. I have had alerts when flying straight and level where the very first audio alert was for a tower 0.4nm away. No icon, no alert text box, no audio tone until then. Then it all happens at once and I get the "schwing!" emergency alert at 0.4nm. Are you kidding me?
I was flying with a friend at low level to the local grass strips a couple weeks ago, and on climbout after takeoff I see a tower just left of our course, taller than our altitude, less than a half mile away. I looked at the 740b and there it was on the map, circled in red and black. No alert at all. My friend has a 720 in his airplane. I said "Hey, are you getting an alert for that tower?" His response: "No, but I'm not surprised. iFly alerts suck." So I don't think this is just me. I previously had a Garmin 496, and all the alerts were super consistent and accurate. The iFly alerts are night-and-day from that experience.
If there is a setting to fix this, please let me know. I have been living with these terrible alerts since I bought the unit, and frankly I just don't trust the 740b to keep me and my passengers safe unless I babysit it all the time.