I use the J-Tip exclusively for locating boundary corners and have for several years now. It's a huge part of the field approach to my business model. I agree that it needs to be simplified.
For now, I'll say that I use the Z direction (as it helps eliminate signals from fences and other objects) but it probably hurts when broad area search compared to XYZ. I use differential which means that it determines the polarity of the object instead of the user specifying a polarity. I use the clear button often. Currently there is no sensitivity setting. The tones are scaled based on the strongest signal you pass over from the last "clear". So if the strongest signal you pass reaches 14, then the tones are scaled for zero to 14. Then you pass over an object with a strength of 100, then the signals are scaled from zero to 100. So the meaning of the tones changes constantly, which is a frustration of mine. Why is it like this? It's designed to constantly pinpoint the strongest signal in the search area. Each time as you pass over, the strongest signal is the highest pitch tone. Javad was sure this was the best approach, but for most field operators we know that the strongest signal is often not the object we are looking for. My workaround has been to watch the signal strength bar on the screen. I can watch for a small rise in signal strength even if it isn't the highest signal strength I've passed by. I also use the clear button a lot. We've been discussing the need for letting the user select the "sensitivity" which really doesn't change the actual sensitivity but would set the scale of the tones to some fixed values. For example the very sensitive setting may go from 0-10, then next might be 0-50, then 0-100, then 0-200 or something like that. Any values above the maximum number in the scale would simply peg out at the highest tone, so with the most sensitive setting a 10 and a 30 and a 400 would all sound the same. The signal strength value would still show on the screen, so you'd still be able to see a difference in a 10, 30 and 400, you simply would not hear a difference at that setting.