This is an interesting thread. I have both a Sovereign and a White's PI Pro, so I think I can chime in here. Both machines can hold their own on gold. I'm from South Florida, and I would say 90% or more of beach hunters here use the Excel (Sov) - with the other 10% either a PI pro or Aquasound (locally produced TR water machine). The excal users seem to do awfully well on small golds and chains too. I have used my PI and have found really, really deep golds, some of them have been very small or thin but most aren't. The sov can't get as much depth as the PI but I have found small gold items many times with it nonetheless. The Sov/Excal offers such good discriminating abilities that the PI's don't have and can still get small gold. It's a toss-up I guess. I would give the edge in raw depth to the PI, since I can go over areas where excal users have been and still get very deep targets, but obviously at a price - I get all the iron junk on the beach. I'm keeping the world "safe from bottlecaps" as I say. PI users have to be willing to dig a lot more crap to get the goods, that's for sure. Most hunters just aren't willing to do that, unfortunately.
Gold Chains, again, I would have to give the edge to the Excal. I have been hunting with the PI Pro for about 8 years now, and I can count my gold chain finds on one hand. And Excal users I know seem to get chains quite regularly. My other gold finds are in the hundreds through the years, just not many gold chains period. Maybe it's luck or I'm a lousy hunter, but either way, I have to give the Excal some credit, it can find gold pretty darn well.
Thanks,
Mark