I'm not an Explorer or even an E-trac user, but, being in the game for a while, thought I'd chime in.
I'd have to agree with Iron Patch's statements. At some point it is JUST about the money on these newer machines - FOR ANY BRAND OR MODEL!!!
Example; I am a long times White's user. Is the new & "improved" V3i THAT mucher better than the "old" V3? Methinks not

Is it even better than the DFX or XLT? My opinion, very, very close.
I was considering purchasing an Explorer or E-trac initially. After much reading, the only difference I can see on the E-trac is the ability to upload one's programs to their computers. Again, never used one, and I know it's definitely top-of-the-line, but, that's really the only difference I see. To me, it's just another "bell and whistle". The "sizzle".
Detector manufacturers are in the business to make money. LOTS of it. Capitalism at it's finest. Nothing wrong with that. So how do they do it

Simple. Every now and again, they will come out with a new color, a more "ergonomic" design, easier menu's, etc., etc., etc. And the pitch is normally this..."It's a must have. Better depth. Cancels out more garbage, etc.". Very few people (except for the "old hands" or detector buffs) will actually care about or even use these upgrades.
And again, just to be clear, I am NOT slamming Minelab here. It's across the board. All of this stuff about which has the most depth, better recovery speed, etc. is very important. However, most of my best finds over the years were in the 6 inch range or lower. Go figure
It all comes down to this people...Get a quality detector, learn it like the back of your hand, find some quality spots and I'm pretty sure you'll be happy with the results. Don't believe all the hype kiddies.
As the late and great Mr. Barnum once said, there's a you know what born every minute