I have had no problems with the knobs on either of the Excals I have owned, but I did replaced the threshold on/off knob on mine with a larger knob sold at Radio Shack, it made it so much easier to adjust the threshold in the water with wet hands.
I never use the pinpoint, I always have volume set at max and I always search with disc at 1 so I did not worry about replacing those on the one I currently have, the first one I owned, that I sold came with all the knobs replaced with the larger knobs already on it, the seller told me he replaces them with the larger knobs because they were easier to adjust. I never had a problem with those knobs either.
I currently own 2 Sovereign GTs, (1 is waterproofed) and I have owned 2 Excals, (still own one), I would not hesitate to buy another Excal or Minelab if a good deal came up. I bought one of the Sovereigns new, the custom waterproof one I bought was used, seller was going through a divorce and needed the cash. I got a great deal on it, cost me $600 including the WOT coil and it was new when he customized it.
Both Excals were used, and ever detector I have bought used arrived in perfect working order......
If you watch you can find some good deals on used Excals from highly trust worthy people here....
