I'm new with the E-Trac but before I even read Tom's message I was already thinking of some of the things he mentioned. I have been running a lot of auto +3 as well. It is usually around 24 to 29! When it's in that range I run at manual 30. I've checked 7" and 8" targets from manual 30 and they don't hit well with auto below 25 to 27, depending.
I do get a lot more iron falsing and jumpy targets but coming from a T2, a little bit of noise on the E-Trac is still a lot quieter than a normal running T2. ehehe When I run the sensitivity hot or even if it's in auto and up there, I find that running a lower discrim pattern slows me down SO MUCH. (say at the 28 on down line). I find myself checking too many signals, but I guess I'll gain trust in what I'm saying and that will pass. Anyway, I run pretty close to the stock coin program but open the top up a bit. I have found fast off helps and I just keep trash on high and that gives good separation. Also, with fast off (and I've compared signals with it on and off on 7" and 8" targets) the hit is cleaner and a bit longer. I was afraid to have fast off coming from "faster" machines but the E-Trac clearly separates well in trash on high. I run deep on as well.
What I find interesting and have seen it mentioned here as well is that when you run manual you can really slow your swing down. With manual sensitivity I can go really slow and it hits them cleanly. It doesn't seem to like as fast a swing. Not sure why but it must have to do with the three channels being saturated or the like. In auto, even on 8" targets I can sweep quicker over them and they still hit fine. With manual sensitivity I can go really slow and it hits them cleanly.
Like I said, I'm new with this machine but having run a V3i for months, running an E-Trac is really easy so far. And, I really really like the sounds, hated them in videos as they were so different. But now they say a lot. Not saying you can't set it up wrong but when you change a setting, if you check it on a deeper target, you can really see a difference. I actually video'd what I thought was a deep coin. I was barely hitting it running sensitivity at 30. I dug a 5" deep plug and it was still in the plug! The signal was being overwhelmed by what was below it. That was the fog in the headlights and I was BARELY picking the target up. I only dug to learn the machine. It was terrible sounding and not very consistent. I then started playing around with auto with no + or -. I found it was very very clean sounding on the mid range 4" - 5" targets and it of course quiets the iron below.
Last thing and I hope I didn't get to far off topic. When I get to a site sometimes I just open up the discrim to hear what is there. Then I play with the sensitivity to see where the deeper iron starts to quiet down at. I keep that as a reference point and can work around that number.
Really fun machine to learn.
Albert