Here is a cut and paste from an article I found on the net. Would post the link but not sure on the rules:
Fisher F75 vs F75 LTD vs Teknetics T2 vs T2 LTD
POSTED ON JUNE 28, 2013 BY MARC
How are these different and which one is for me?
Customers often ask us “what is the difference between the Teknetics T2, Teknetics T2 Ltd, Fisher F75 and Fisher F75 Ltd. – and which one is better?”
Fisher F75 vs Teknetics T2
It seems as though everyone you talk to and every other forum post you read has a difference of opinion, when trying to answer this question.
You can quickly find yourself sinking deeper and deeper into a quicksand pit of confusion and frustration.
The truth is, everyone will have a different experience using a machine based on things like their location, type of hunting, machine settings, etc.
So it’s much easier to discuss the facts and look at the features of these machines rather than jump into the deep end of the pool of conjecture and opinion. As Joe Friday said “Just the Fact’s ma’am”
Before diving in and in the interest of full disclosure, the Fisher and Teknetics brands are both owned by ‘First Texas’.
Now we can dive in.
Teknetics T2 Standard
Let’s start with the easiest one – the standard T2. Simply put, this machine is no longer in production in the U.S market. It has been replaced by the T2 LTD.
Now let’s take a look at the Fisher F75.
Fisher F75 vs. F75Ltd.
The main difference between the F75 and the F75 Ltd is that the F75 Ltd comes with a faster processor allowing the Ltd to have a “boost process” and “cache locating process” which you will not find on the F75.
What does this mean?
Boost Process is an enhanced sensitivity mode, useful when hunting regular-sized deep targets (like coins) or on a site where vegetation or terrain require you to raise your coil several inches above the ground.
Cache Locating Process is an enhanced sensitivity, slow speed mode, useful in locating large deep objects, while sweeping the search coil several inches above the ground.
Now let’s compare the F75 LTD to the T2 LTD.
Fisher F75 Ltd. Vs. T2Ltd.
The F75 Ltd saves all settings even after the power is turned off, while the T2 Ltd will not.
The F75 Ltd has 3 search modes Static All Metals, Motion All Metals, and Discrimination; while the T2 Ltd has 2 search modes All Metal and Discrimination.
The F75 Ltd has a confidence bar; 6 segment graph that indicates how confident the detector is of the assigned 2 digit identification number.
The T2 Ltd’s discrimination is adjustable from 0 to 80, while the F75 Ltd’s discrimination is adjustable from 0 to 65.
The T2 Ltd has an expanded iron range from 0-39 (desirable amongst relic hunters), while the F75 Ltd’s iron range is 4-12.
The T2 Ltd has an adjustable pinpoint sensitivity mode whereas the F75 Ltd does not.
When the feature comparison doesn’t get the job done and all else has failed, forcing me to cannonball into the deep end of conjecture and opinion about the F75 Ltd and T2 Ltd, I cling to a life ring tossed into the pool by Fisher and Teknetics Lead Engineer Dave Johnson.
Why? Because Johnson knows best, after all, he created ALL of these machines.
Dave Johnson First Texas Metal Detectors
Dave Johnson Chief Designer: Bounty Hunter, Teknetics, and Fisher brand metal detectors.
“Despite their obvious similarities, the T2 Ltd and F75 Ltd have rather different “front end” circuits.” Says Johnson.
“The F75 Ltd is slightly hotter in an air test with no electrical interference, but by a small enough margin that it’s hard to prove that margin actually exists under actual field conditions.” Continues Johnson.
When it comes to which machine is deeper Johnson explains that it “is a function not just of the electronics, but also how you set up and use the machine under what conditions.”
It’s not possible to set up the T2 Ltd and F75 Ltd exactly the same in discrimination mode, because of differences in scaling.
“In the hands of some users under some conditions those differences would give a slight advantage to the T2 Ltd on low conductors.” Said Johnson
Thankfully Johnson simplifies the discussion by adding “Both machines are general purpose machines, but between the two, in the hands of most users the T2 Ltd will be slightly better for relic hunting and gold prospecting whereas the F75 Ltd will be slightly better for coin shooting.”
For the vast majority of us it boils down to what types of hunting we plan on doing.
If you plan on Relic hunting or Gold Prospecting then it seems as though the T2 Ltd would be your best choice.
Conversely, if you plan on mostly coin shooting then it would seem that the F75 or F75 Ltd would be your best choice.