Dew,
I have been an avid beach hunter here in S. CA for many years. If you are talking performance on a mineralized sand beach in terms of FBS, I have found the combo of choice to be the Explorer II with the Pro Coil. It will go deeper than the original Explorer, the SE and the Etrac. I know several other hunters, a couple of whom love their SE's and Etracs more than life itself, who have come to same conclusion. I'm not sure what Minelab did to the II, or "undid" to the SE and the Etrac, but my finds have been the best over time with the Explorer II.
Also, the Pro Coil is vastly superior to the any other coil I have used on an FBS machine. For the record, I have not tried any of the SEF coils.
As to BBS vs. FBS, that's a tough call. Andy is the real expert on that (and just about everything else involving anything Minelab as well). I found an Excal or Sovereign with a WOT to be top drawer in terms of performance and coverage, but either configuration is just too darn heavy for me. And yeah, I've tried all of the various configurations. Any hip mounting of the BBS machines, even with strain relief on the cable, will eventually lead to the cable having a problem. Plus I got tired of the spare tire around my waist. Straight shafts are better balanced but weight is still weigkt. The Explorer II, with the very lightweight Pro Coil, gives me just what I need.
Oh and one more thing. If any "expert" tells you to run the Explorer in manual on the beach, including Minelab itself, nod, smile & then DON'T DO IT. Run semi-auto. I don't know why it works, and neither does anybody else, but it will be more stable and deeper than manual.
Lastly, I have no knowledge or experience with regard to the new CTX 3030. While I was involved in many projects with Minelab in the past, including the Etrac, SE Pro & X-Terra's, I had no involvement in the CTX 3030 project. It certainly looks to have some nice features. However, if the early reports are that it is a nice machine but is essentially an Etrac with added features, then it would not be my choice for hunting a saltwater beach, especially one with black sand. If you need waterproof, I would go with an Excal II. It is a great machine.
Bill (S. CA)