Long Winded Approach
Greetings
Ignorance Denied,
As you already know you are attempting a difficult decision though your pragmatic approach will serve you well. I am surprised that one obvious suggestion has not as of yet been put on the table, attend meetings at a local detector club. As I suspect you understand every user tends to promote the brand/model they own when it has served them well and this will be true here on Tnet as well as at any club you might attend.
It is good that you are "I am highly techical oriented, and quite a bit OCD, so whatever I end up with I will work to the best of its abilities" and you are correct as these attributes will be of benefit to you though, as you know, the OCD can drive you nuts with some things and detecting is one of them. I would say you will be better served with one of the higher end machines due to who you are. I suspect you are aware that for "prospecting" you are better served with either a VLF machine or a Pi machine. There are a few dual purpose machines that work fairly well, they find both raw gold as well as coins/relics/jewelry though I believe the more expert types indicate they prefer a pure prospecting machine for prospecting and a dedicated coin/jewelry/relic machine for that arena.
I noted an interesting article on here this morning in Metal Detecting something like "My AT Pro owned by Minelab". An AT Pro owner encountered a Minelab owner on a beach, they talked and the Minelab owner invited the AT Pro owner to join him. The Minelab trounced the AT Pro in depth and target identification. Not that the AT Pro is bad machine, it was just outclassed by the abilities of the model Minelab it was competing against. It comes to mind that there are at least three folks on Tnet that it would be helpful for you to PM: Steve Herschbach, Terry Soloman, "Lanny" and "Gentleman" Jim Hemingway and as you can tell I realized another seasoned veteran of high repute to add to the list. All of these fellows can be found in the Prospsecting for Gold under Metal Detecting area. Steve's last post is about five or six down from the top and his name will be off to the right. Lanny & Jim will be found in "Bedrock and Gold, The Mysteries" blog of Lannys and Terry is at times a bit harder to find on here so try:
Metal Detecting, Gold prospecting, Treasure Hunting or
Info@ArizonaGoldAdventures.com. Now all of these chaps are into prospecting in a big way however they do dabble with coins and such trivia from time to time, especially Terry. Terry you will find is a proponent of Tessoro products however he owns a Minelab GPX5000 and likely has the arm muscles to prove it.
Me, I'm a White's chap though, back in the day, originally I built a few detector projects from electronics magazines and I have owned one of the original Gold Bug's (like the BG 1). Then I found a White's 6000D and I was indeed hooked. It was stolen so I purchased an XLT and about that time my life changed so it has seen a lot of closet time. I am Not skilled with its use but I have found coins with it along with lots of trash and that is typical for any in city detecting. I backpack as much as possible every summer and if I could find a 9 month position 'working' and have 3 summer months off to backpack I would take that job though, preferably it would be in the Medical Device Catheter field. And the backpacking brought me into Gold Country so I dabbled with panning and regularly found a few flakes. After one particular panning incident I purchased a 2" "Portable Suction Dredge" and brought it and its sundry attachments as well as my general backpacking gear or about 200 lbs of stuff into the canyon's I am prone to hiking. Then I finally purchased a White's GMT and did not really pay enough attention to my learning curve so it took me awhile to place the coil over gold but I did. I now believe in that particular tool although it does have short comings just as all machines and humans do so I'm toying with the idea of a PI machine. I am only looking right now and I'd hoped the new Garret machine would Require other companies to come out with their Upgraded model but I suspect this will not happen though it is far too early to tell.
Anyway, I've done my usual long winded approach to an answer and I hope you will be able to dig through it and come up with something useful. We, all of us here at Tnet, extend our greetings to you as more or less a new member and would SO appreciate your including us in on your search and what you come up with as far as a machine('s) and of course please show us some of your targets and share with us your experiences 'Out There'!
Regards...........................63bkpkr

Prospecting my way.

Results.

Typical location type for myself, I like water!