HI RON: In many ways comparing a Garrett with other much more expensive detectors is rather like comparing a dune buggy with a hummer. It only becomes practical when you consider the locations and reasons in which either may be used. both are off road vehicles but --------.
In it's element the dune buggy can hold it's own, therefore it is quite satisfactory under those condition's.. The same holds for the Detectors.
There are / can be many valid reasons for purchasing a Garrett, besides Garrett's excellent reputation for quality and follow up.
In my case, I chose it simply because it will perform just as well as a much more expensive one in the areas where I intend to use it. A side, but important issue, is that it will have to go by mule travel and since there are no repair services, I will have to do any minor electronic ones, as well as the physical ones myself. Also, it relatively simple to set up and use, an important point for me since I will have to show my crew how to use it effectively, a short learning curve. Since most have just recently mastered how to turn a radio on and off, this is important.
Based upon these and other reasons, it is the only logical choice for "me", but it obviously would not be for others under different conditions. Each will have to decide for themselves, based upon many factors such as the inputs from you and the others.
As for knowing about electronics and mineralogy, I presently own 4 Au, Ag, Pt and one Cu, Au, Ag claims titled for the next 50 years, and am presently investigating and filing upon 3 virgin Au placers.. A year in military electronic school, and subsequent experiences, qualifies me to a minor extent to make an intelligent choice, I am sure that you will agree..
Check the following picture for the assays on one of the holfdings.
Don Jose de La Mancha