the Owner's Manual. It's only a metal detector and, like the others you have, will only be required to do "the basic stuff" until you learn it.
I know, just ordinary things like ... detect metal ... seems to be rather simple to state, but each type of detector design does it differently, and some will handle some things better than others. The main questions to ask when learning any detector are really the first questions you ask yourself when shopping and after buying. Things such as:
I wonder what different detectors might do?
I wonder if this or that model will help me find what I haven't been finding?
Maybe a new design will help me get more silver or gold jewelry?
I sure hear great things about the XXXXXX, so I wonder if it will work better than my XLT or Ace 250 or Explorer SE Pro?
Those are what you might ponder before buying, but only you could have other, more particular questions that relate specifically to each of the models you currently use. Once you buy a new detector, new questions come to mind. Some relate to earlier questions as you compare it with other models, and new general questions related to use. Thoughts like:
What is different about the VDI readings compared with what I am used to?
Am I getting better depth, or am I getting less depth than before?
This uses a different sweep speed or has more give-and-take in sweep speed. I wonder why?
Should me new detector be noisier?
Wow, this unit has different audio response, I wonder if it is better? Maybe it is, maybe it isn't?
Now that I have this new detector, I wonder which model it will replace? I wonder why I got it? I wonder if what I have, or had, will do a better job for my types of hunting than this unit does? What's the difference in performance from what I am used to?
Other books might not answer a lot of these questions, or other questions you might ask yourself. Metal detector selection can be a rather interesting adventure in a shopping experience. You might have to be careful because if you get overloaded on the number of detectors you own and use, it can call for a lot of field time to learn them, learn their differences, and master them. Sometimes people get too many units and never put in the time to really get to know what they have. Never really master it.
I'd simply suggest reading the Owner's Manual and make sure you understand what it is talking about as it describes features and performance. Next, compare what you are learning with what you are used to and then you can see if there is a performance edge, or know which questions to ask. Direct those specific questions to your detector dealer, to someone who might have a good answer, or fire away with specific questions on a forum.
Also, think about your detecting experiences or testing and write some notes. Refer to your own notes when you double check a 'test' or comparison with a different model and you will learn from that, alone.
The MXT has been a very good model for White's, and after working with an early prototype of what became the MXT Pro, I was favorably impressed. Then, the final product was even better! More simplified touch-pad controls, and the best feature (other than the excellent back-light) was adding the Ground Grab touch-pad. That makes one-handed operation and quick updating of the GB very quick and easy.
Since your MXT Pro "is coming" it seems you probably didn't buy it from a local dealer so you might not have any local dealer help learning it. After you get it and play with it a while, shoot me an e-mail. I'll work in a day to drive up your direction and we can do some detecting and I'll give you what help I can.
Monte