Ok, a lot of good info in this thread already... I'm sure you still don't know which way to go though... well, everyone likes what they like... and it's true if you learn the machine you HAVE it will work wonders for you.
Either machine is going to go deep and give you that signature Minelab sound.
I detected with the SE Pro for a whole summer/fall/and half of a winter... since then I've had the E-Trac.
What you get with the E-Trac is a slightly different angled handle... I would say more confortable.
You also get a much faster and easy to navigate menu. The sluggishness of the SE Pro's menu infuriates me (I'm an electronic engineer, and as a user I just look at it and say.. "this is not what I paid over $1000 for, I wouldn't have let this happen")
You get to have the Smartfind graph AND the digital Ferrous and Conductive numbers on the screen at the same time. You can also invert which one is BIG, so you can have BIG graph and small numbers, or BIG numbers and small graph... I really like having the big numbers at dusk and for night hunting. Oh hell, I like the numbers a lot on the E-Trac because it's very accurate with the numbers. The SE Pro will jump around and you have to really interpret the "dance" of the cursor on the smartfind graph more than relying on the slowly updating numbers. They changed the algorithm in the E-Trac to flatten the ferrous response so that all targets pretty much have an FE of 12, give or take a number. Since the CO scale is expanded from 31 to 50, you get more resolution there to try to figure out what is what, and when you see a 12-47, you know it's a quarter... Andy Sabsich's book details this algorithm change much more if you want to read about it. When the E-Trac hits on something... it seems to really lock in on a number way better than my SE Pro ever did.
The DEPTH and TARGET info actually update in pinpoint mode, and they update more reliably when in your normal motion mode sweeping over a target.
The USB thing is pretty much a gimmick, unless you are into complex patterns... then maybe it would be useful. I have not used it since owning the E-Trac. I just run the default coins program... bingo bango.
You can easily switch to the Quickmask mode to open up your screen on the E-Trac... and while you can do this on the SE Pro, you have to press the button 3 times instead of just a simple toggle ON/OFF with the E-Trac, and because the SE Pro is slow... well, so is just switching between menus. Also, you can mask more than just the ferrous content in Quickmask... you can pull a mask over for the conductive parameter at the same time. I usually just have a FE mask, but in heavy trash (especially foil and pull tabs) it's nice to pull that CO mask over to help isolate the coins.
But wait, there's more!
With the addition of the Trash Density feature, you'll actually LIKE to use masking and patterns. When the Trash Density feature is set to LOW, an unmasked target can be silenced if a neighboring masked target is a stronger signal. When the TD is set to HIGH, it's just the opposite... unmasked targets will sound no matter what... The first time I used an E-Trac, I was amazed by how quiet it was until it hit a good target. This is the feature that really makes the E-Trac worth getting, as if you didn't have enough reasons.
Sure, the E-Trac is more $$$... but I'm sure you already know that and just want whichever detector tickles your funny bone best.
At the end of the day... there is no magic answer... it will be up to you to pick a detector, and make it work for you. If you get it and it doesn't perform well... something's wrong. It could be the detector is just defective, but most likely it will be because you have not given it time to sink in, have not had the patience during the learning process or just have a mental roadblock for whatever reason. All of these top of the line detectors work VERY well. Some have interesting features that seem to set them appart, but if you went on a group hunt with all of them... I bet everyone would average the same number of great finds.
No matter what you decide MasterEagle22, you know you are getting a great machine and it's just going to take time to become "one" with the machine. Good luck and Happy Hunting!!