If you never hunt a single spot more than once or twice there is no need to fret about your detector in my opinion. That is as long as the detector you use is a capable detector. The AT Pro and Equinox are very capable detectors. So are lots of others.
If on the other hand you don't get many permissions or only hunt public spots you hunt a place until it's cleaned out as best as you can. By the way that's kind of how I hunt. Not many permissions and public places and I hit them until I can't find anything else. I am up to three detectors now with another one on the way.
Some one told me the other day a guy that has one detector and knows it inside and out and gets the coil over targets will find lots of stuff. I believe that is a true statement. I also believe if you are serious about detecting you need many options. You might like running let's say an AT Pro the best, but if you go over a spot in multiple directions multiple times and clean it out or find nothing is there any good targets left? You will never know unless you hit it with a different type detector. I have a Etrac for yards and cleaner parks. Some places in my opinion are to trashy for an Etrac. I use a Nox in those places. If I knew a guy had wore out a place with a Nox then a Nox is not going to be my first choice if I was going to hunt it. I think a person limits his finds by owning only one type of detector.
So I have the following. Equinox, Etrac, Nokta Impact, and soon a Tesoro Mojave. I would say each of these detectors are unique, and each could find something the other three might not alert you to dig. You could exchange different brands or types detectors in that group. The main thing is no two are exactly the same technology. For me that is the final answer.