Hey there Hawg,
I'll throw a little feedback your way. I used a CZ-6a for a number of years in the mid-90's until just after 2000. I really liked it. It was capable of excellent depth, had very good target separation capabilities, had a Target ID that was functional (I'm not a big fan of segmented TID's), and was all put together in a pretty good package. I found a lot of coins and tokens with that detector. BUT, I dug a TON of rusty nails. My CZ-6a loved rusty nails. It had target separation good enough that I would find coins near other targets, but I wouldn't know if I was looking for a good deep target adjacent to a bad target or looking for a pseudo target out on the point of a rusty nail. I never found a way to separate these 'fringe' targets either with the VID or the audio.
One day I was out hunting the backyard of a very old house and had dug some deep coins and a bunch of rusty nails; which was frustrating me. I would have a plug several inches deep and would be digging around looking for the target. Then I would find the point of a rusty nail just protruding into the side of the hole. I had finally had enough. I went out and visited the local minelab dealer and had a long talk. His suggestion for me was to move into an Explorer, Minelabs latest detector, as it had a more unified package than the Sovereign (which he used) and it would make an easier transition for me. My initial impression of the Sovereign back in the early 90's wasn't good. I was debating between the CZ-6a and the Sovereign. To me the Sovereign was very heavy and it looked amateurish due to it's piece meal approach with a housing that could be located just about anywhere, an aftermarket meter that stuck up like a sore thumb on the searchrod and way too much cable to be practical. It looked like it was manufactured in somebodies garage.
Anyway, I made the move to the Explorer XS and I immediately noticed a couple things. First, my rusty nail recovery dropped by 80 or 90% and second, I started finding A LOT more silver dimes at depth. In addition, I began finding coins that were on or adjacent to rusty garbage.
So to me, the iron mask capabilities of Minelab's multifrequency detectors works great. And at least the Explorer XS that I used found targets deeper than I had found with my CZ-6a on a much more regular basis. As for the Sovereign, all the reports from longtime Sovereign users is that the depth capabilities of the Sovereign and the Explorer are essentially equivalent depending on coil choice and user capability.
Personally, I wish I would have stepped down the Sovereign road rather than the CZ-6a route way back then. I believe I would have decreased the number of trash targets that I dug and increased the number of good targets. But hindsight is 20/20.
Now I'm not a beachhunter, but I have observed that the Sovereign, and it's sister the Excalibur, are extremely popular with the beach crowd. There's usually a reason for that. If you have friends that used Minelabs, how do your finds compare at the end of the day? How about the trash pocket? Are you digging a lot of rusty nails and the like? Less time digging trash means more time digging good stuff.
I wish you luck with whatever you decide.
Rich (Utah)