I've been a tesoro user for a while now, but would like to try a TID machine. Played with a ace 250 before but wanted to try something else(better). Is there much benefit to getting the 70 over the 50 besides the extra coil option, the increased notch increments, and more resolution in the ID numbers. How good are the tones, I have a Golden umax for a tone machine now, are the tones any better on the 50 or 70. Thanks