I bought a 12" Excellerator coil for my Sov because the stock 10" Sov coil got less depth than the coil on my stock cz-70, my stock Compass Relic & Coin, and my (ex) 8"X9" Tesoro Tejon. The same thing was true with the Explorers when using their stock 10" coils. In fact, the Sov gets a bit better depth than the Explorers because of all the extra functions slowing the Explorers down a bit. Maybe that's why so many of the Excellerator coils were exclusively and specifically invented to be sold to top-of-the-line Minelab Explorer and White's DFX owners?
I'm not bashing Minelabs or White's here, just making an honest and real-life comparison. In fact I used to work in the engineering of White's circuit boad design at one time in my life. Most Minelabs and some Whites do handle bad soil very well, but they are actually not any depth demons like the Tejon, cz3d, Garrett 2000 and 2500, or F-75 with a big coil on them in moderate soil, that's for certain.
I gained about 2" with the Excellerator coil, but in some cases the sound the detector makes is a bit iffy or should I say "swishy"? The vague sound almost makes me feel like barfing, I like things to be more profound and distinct, something that Minelabs are not notorious for in the first place.
A WOT coil works a lot better than an Excellerator, but they cost a lot more $$$ too. Somewhere in the neighborhood of $400 or so for a good one, while the Excellerators are about $200 for the same size. If you own a Tesoro from the SilveruMax on up, you will probably achieve depth as good (or better) with Tesoro's bigger coils- - on a Tesoro- over the Excellerators used on White's or Minelab detectors. Maybe not so with the WOTS, they are some really good (and deep) coils for the most part.
Hope this helps.
EasyMoney