I'm new to metal detecting and was just given two older Garrett detectors. Both are in excellent shape and seem to be working fine. My question is am I wasting my time with these older models or should I look at a new one. I was looking at the Garrett Scorpion because I would like to nugget hunt as well as occasional coin/relic. Pros and cons on my units?? 1.) Garrett ADS VLF/TR Deepseeker and 2.) Garrett American S4. Thanks Steve in California