...mine is one of the earlier units, which came from the factory on the "hot" side to start with. His changes only enhanced that latent abiltity. As to the chronology of the Classic series, what units have which changes, etc, honestly, I dont know all that stuff. Bill DOES.
I hope at some point to advance beyond "beginner"
The Classics are for EVERYBODY. Used as tools to find metal, they have a long standing reputation of success. I got this CIII because I had one in the past and I knew I liked it then. I had done the GB pull-out on that one myself, and I considered it a valuable modification. I still do, because with the inherent stability found in the Classic circuits, there is little fuss to be made over manual GB. With just a little educating, any average detectorist can figure it out and benefit from having the feature.
Same with the other mods he does. The THRESH adjust, for example, is also a bennie to have and works in concert with the GB. Besides, according to Mr Bill, Whites shipped the Classics with the THRESH overly loud in the first place, since Whites expected that newcomers (and others, perhaps) would be using the instrument without headphones - so it needed to be loud to be heard! Using headphones (as you should) requires that you need to have some control over the amplitude.
I'm really intrigued with his ability to tweak the sensitivity of the improved circuity even further.
They say that "...a fool and his money are soon parted", and I suppose you are worried that you would be wasting money to have him "modify" something that is already at its best.
Through discusions with Monte and others, I learned about all the changes that could be done to a Classic detector and figured, that for $70, guaranteed, what Mr Bill offered was a real value. Did I really need to do that?
Possibly not. I do know that I wanted to have all that was available from the instrument on tap in case I chose to employ it. I mean you can't use what's held back from you, right? I could have done the mods myself and saved the money - except the boost enhancements. As Bill says in his response, just having the GB and THRESH options made available to you is a real boon in terms of usability.
Would I recommend having them done by a true professional, like Bill, who knows more about getting the most from an already good instrument? More than you or I will ever know? In a heartbeat! I'd do it again tomorrow, should another good deal on a C-model come along.
If your C-model is as hot as it already can be, then Bill will tell you. If it can be made better, he'll do that for you, too. This is one "fool" who heartily endorses the man behind the work.