Sovereign, first...That seasearch coil is an awesome coil from what I hear. Very stable. Many guys loved it so much they cut them off Excals and used it on their Sovereigns. You can cut off the fins to save more weight too. Check the Coil sticky first page for info on it.
I think Ron *might* have been mistaken on the BBS/Tornado 8" thing. Yep, that pic sure does look like the BBS and Tornado 8" coils are the same coil, but what I suspect is that Minelab was throwing the old BBS stickers on the first productions of the new 8" Tornado until they used up that stock of stickers, and then they converted to the Tornado sticker. Reason being? I've held the old 8" (it and the Tornado are actually 7 & 1/4" in size, which is why they are said to be fantastic in heavy trash, and still get outstanding depth...I've read of coins a foot deep)...Anyway, I've held the old 8" Tornado in my hand to repair one, and I can tell you it's a frick'n boat anchor. Everybody says the Tornado 8", just like the 10" Tornado, are so much lighter and better performers than the old BBS versions. Ron says both of his coils were similar in weight, so I suspect he got an "odd" newer Tornado when Minelab was making the transition and was still throwing left over BBS sticker stock on them.
But I'll say this- I've read some say the old BBS 8" coil was a much better coil than the 10" BBS coil, and was actually deeper for people. So I ain't saying it's a bad coil. I've seen it do some damage water hunting on an Excal, but just the same I'd opt for the 8" Tornado myself, as it's said by many people to be a better all around coil, not to mention a lot lighter.
Wpruden, the 180 meter will easily tell nickels from tabs. Nickels range around 143 to 146 usually, some as low as about 136 or so, but tabs start at about 148 or 149 and go up to 169 99.9% of the time. Never owned a detector that could distinctly ID nickels from tabs like this, and the audio is also very telling for nickels. I'm not even aware of any machine thus far that has as high of resolution from foil to copper penny as the 180 meter on the Sovereign in terms of conductivity resolution. It can be deadly for avoiding trash while hunting rings or such.
Far as coins above copper penny, I only care to know it's a coin because if it's deep or it's shallow but in trash I'm digging it no matter what kind of coin the machine thinks it is. The conductivity between various coins above zincs is so close that any one can read like another due to minerals, being on edge, masking, etc. I've dug a ton of silver dimes in the past that a machine told me were copper pennies or even zincs. I never trust that when old coin hunting. Only thing I want to avoid is zincs when in the mood, and I can do that.
Also, I've noticed...You can often tell what kind of coin by how fast the meter gets to 180. Copper pennies will climb...177,178,179,then finally hit 180 if you watch the meter when first wiggling over it. If you missed it move the coil away and make the meter reset so it's not 180, and then move back and wiggle. You'll see the steady climb. Clad dimes hit 180 sooner. Quarters even faster if not instant, and silver dimes or quarters usually will go 180 the fastest. Like bang- 180 right off. The silver WL quarter I dug a few months back was an instant 180 with no climb that I ever saw. It was instantly "180" when I first hit it, and didn't fight me to do that. Of course deeper silvers are going to climb slower maybe in some situations, but then you judge- how deep does this coin sound? And how hard is it to get to 180? All coins will get equally slower in that climb at depths, so you can adjust the "how fast is it climbing" scale in your head based on depth and figure out still what it might be. Often silver will still bang 180 pretty instantly at depth, but not always. My experience so far anyway...
8" Tornado and the old older 8" BBS. I have the S-5 and the Ultimate...and I think I will be fine with the Seasearch and BBS 8". Now I need to start moding old Sov meters...or maybe I'll leave them at the 550 scale...