Most of these weights are actual numbers from users, not listed company specs...unless noted. I am shocked at the light weight of the 12x10 Sovereign (non-FBS version), not to mention the Sovereign 15x12 compared to some others. It appears the FBS versions of these coils are a good bit heavier. As you can see, the 12x10 is about the same weight as the well earned light reputation of the Sun Ray S-12. In fact, it's a good bit lighter than the S-12 without the coil cover on! Further, with so many people raving about the light weight of the FBS Pro Coil, you can see it doesn't really have any weight advantage over the 12x10 for the Sovereign.
Much of the improved separation and performance of the SE and Etrac I attribute to the excellent Pro Coil, and you'll see the same kind of performance advantages with the SEF 12x10 for the Sovereign. As I said before, if you handed me a mystery Sovereign with a 12x10 on it I would have bet money somebody sped up the processor with seemingly better separation, reaction, and response. Sound familiar to what is said about the SE or the Etrac over older Explorers? I bet much of the improve over prior Explorers on those machines has more to do with the coil than anything else. We all know the 10" coil on older Explorers was terrible in many respects. The Sovereign 10" Tornado version IMO is much better at separation, pinpointing, and stability. No wonder so many people love the Pro Coil, as well as the 12x10 and 15x12. All great coils in their own right.
With the listings of things like the stock 10" Tornado, old 10" BBS, and the Pro Coil for FBS machines, this would help people make judgement calls as to how much weight a coil they might be interested in should weigh compared to what they have now.
Think I'm finally home after a lot of years searching for my particular needs. Custom 1.5 lb lighter 
Sovereign GT (easy to do by just "building" lighter shaft) & SEF 12x10 as everyday coil. 8" Tornado (actually 7.25") as super heavy trash coil (Very deep & separates better than typical 8/9" true size coils). 13" Ultimate for large fields/beaches on certain days I want to grid faster than even the 12x10's nice improvement over stock for that. Stock 10" Tornado stays on water rig (stock shaft). 
ProPointer. Owned 15x12 & SunRay S-5 (5.5") at one time. Loaned a prior 13" Ultimate & SunRay S-12 (12.5").
Some Oldest Silver- 1835 Bust Dime, 1842 "O" Seated Dime, 1855 Seated Quarter, 1858 3 Cent Piece, 1891 Seated Dime, & another Seated Quarter too damaged to read date. Highest Value- 3 Cent Piece, Seated Quarter, & now 1921 F-12 Standing Liberty. Oldest Coin? Got to give large cents a good look & see. 2013 so far- 1 Seated Quarter, 1 Barber Quarter, 1 Standing Liberty, 2 Washingtons, 1 Barber Dime, 9 Mercs, 3 Rosies. 1 War Nickel. 19 silvers in total, & 1 1872 key date Indian, 2 Bufallos, 1 man's 14K gold medium sized ring & 1 gold chain, with possibility of few 8"+ deep mystery coins being Indians after cleaning.
What matters in life is the journey and not the desitination. How you handle that journey determines if you were a success, not so much what you achieved if and when you finally get there, especially if you made it by stepping on people along the way...
In loving memory of my long haired (wooly) husky Sky. She taught me just how beautiful and pure a soul can be, human or not...
