I just got mine Excal not even a week ago - I'm learning it, but so far, I love it. I'm learning the sounds; it's a little confusing for me right now, but with no meter, I have only my ears to rely on, and in the water, that's all there will be for me to rely on. I am getting used to the feel of it, and am more comfortable with it now than i was at first. I am using it every day for at least an hour - went for three hours today, and was able to ID things pretty well before digging (still finding lots of pull tabs - but I have the screw caps down, have been digging those just to verify for my self right now). Without a lot of time on it, I can't tell you about the negatives other than I plan on getting a straight shaft (any recommendations? Travel shaft sounds like a very good idea for me). The Excal I have is an older one - bought it used; don't know what year it was new, but it's in good shape. Chances are good that down the road I will change the headphones as I have hearing problems (things are either not loud enough, or too loud, plus I have tinitus), and I see where being able to change coils would be very useful. I was told by Synthnut - who I bought it from - to be careful turning it off; people tend to crunch down too hard and it's easy to break the knob. Hearing the nulls is new to me, but it also tells me how much iron I'm passing up - but I don't hear it
So, yes, I'm a newb on the Excal - but so far, I love it, and I'm getting a Sovereign GT soon too. I have a meter for that one, so that might make learning a tones quicker, but I'm not sure about that yet. In the meantime, I'm using it every day, guess at the target, then dig it, and compare those to other similar sounds later (sometimes compare sounds right there in the field).
I really don't see how I did without one before,