As is true with all TID machines the Cortes's meter is often fooled. It is just the nature of MDing. Canslaw often comes up in the $1 coin range, gold can be almost anywhere from iron to zinc pennies. I will say this though, after a little practice you usually have a pretty good idea if a target is good or not. The machine sounds in combination with the meter give you very good idea.
I don't think form all I have read about the Tesoro "Hot" machines like the C and V that the Cortes will get you any extra depth. In fact the C and V may be a little deeper than the Cortes.
I love my Cortes, the only reason I have considered purchasing an additional machine is to get some extra depth. IMO the perfect machine would be a Cortes with manual GB in both modes and the depth of the Tejon and the multi-tone capability of the Golden.
Back to your question, If you find value in the information the display can give, the Cortes is an excellent addition to your arsenal.