A few comments on your pros and cons . . . .
First the CTX is weatherproof, not etrac or F75. - Yes but for relic hunting is that a deciding factor . . . . rain covers are available for either models that will protect it from all but the hardest of rain
The CTX will handle EMI better than F75. - The newer models do a much better job on handling the EMI . . . . older F-75's were notoriis for the chatter but the newer ones have queited down a great deal . . . is EMI an issue in your area?
The CTX is heavier than the F75 or the etrac. The CTX does balance better than etrac though. - Yup, 5.3 pounds is just that . . . balanced or not. If weight is an issue for all day hunting, make a trip to tru swinging one before buying. Weight is the number on reason people have opted for something other than a Minelab even at the expense of performance
The CTX will handle mineralized soil better than F75. - Yes, as a result of the FBS circuit in the same way the FBS circuit aids the E-Trac
The CTX gives more target information than the F75. - More information is not always the better option - depends on the sites and the type of targets you are looking for. A lot of relic hunters swear by the non-metered machines and find a heck of a lot of stuff.
The CTX is upgradeable via internet versus the etrac. - Yes here as well . . . . not sure if actual upgrades will be done this way or if it is only for patches . . . there's always the CTX 3040 for true upgrades
Minelab offers the big coil for CTX. - Yes, but there are several larger coils available for the E-Trac at considerably less money
CTX has lithium battery etrac don't. - But there is a LiON battery option for the E-Trac that not only provides 30+ hours of run time but weighs less as well . . . both are positives
CTX has the wireless box that acts as speaker. Could be beneficial in hot weather. The external speaker system on the etrac has major shortcomings (not very plain). - Not sure a serious relic hunter would opt to hunt without headphones and possibly miss the faint hits from deep targets . . . . there are always lightweight phones if hunting in the summer presents an issue
All three detectors have their pros and cons . . . . . you need to determine which are more important than others and how much each is worth in the big picture . . . . . I'm sure that if you post this question on the Fisher forum you woudl get completely different answers
You will find that the red soil in the Culpepper region will give both the E-Trac and the CTX 3030 fits . . . and this is both from personal experience and feedback from others attending the hunts there. That is some extremely bad soil period!
Andy