Scott --
First of all, I grew up in SW PA (Beaver County), and travel back there often. I will be in town for two weeks in the summer, visiting family and friends; maybe we can hook up for a hunt?
As for your question...I am biased on this, because I bought an Explorer SE Pro last April and have used it since. So, I am used to this machine and its nuances. However, many of my friends hunt E-Tracs, and I recently had the chance to borrow one and use it extensively. I have it now, and use one or the other, depending upon my mood. I have even hunted both in one hunt -- marking targets with one, and then re-checking with the other. So, I have developed at least a little bit of a feel for the E-Trac, though nothing close to what I know about the Explorer. Still, when I grab the E-Trac, I am confident that I can find good stuff with it, and have.
Having said that, I do not personally feel the E-Trac is much -- if any -- "better" than the Explorer. They both have things I like about them, and both have things I do NOT like about them. As for finding coins, I have NOT compared the two on really deep targets IN THE FIELD, but I have in my test garden, and I don't get the impression that the E-Trac is deeper than the Explorer, at least, not by much, if at all. It MAY on occasion give a slightly better "first response" on a deep target, and maybe a bit more consistent of a response when doing the "Minelab wiggle" over a real deep target, I'm not sure. What I AM sure of, though, is that both LOVE to find silver, and both are outstanding machines. I prefer the audio on the Explorer just a little bit more; the E-Trac is very similar, and if you understand the Explorer's language, you will feel right at home with the E-Trac. However, the Explorer sounds, to me, just a tad bit "warmer" or "mellower" or something on a silver coin. But, it's subtle. They can be set up to sound, and run, very similar.
By the way, for those who say the E-Trac is NOT an Explorer 4, I disagree. While there are changes (the E-Trac's orientation of the CO and FE on the smartfind screen is different, and the "normalizing" of good targets FE values to the "12" value is obviously different), they both behave VERY similarly, the quirks are similar, and if you "understand" what your Explorer is doing and why it does what it does, you can transfer that understanding DIRECTLY to the E-Trac. The E-Trac seems to run a bit more "stable," slightly less "chattery;" I also like the E-Trac's handle angle MUCH better than the Explorer's.
That's just my take, after using both. I like them, and you can't go wrong with either; I, though, still prefer my Explorer (though, again, I'm biased; if I had started out with an E-Trac, I would probably like it better than an Explorer).
Hope this helps some...
Steve