Born,
I have a WOT in my coil arsenal. It is a very good coil, and you will be able to find stuff deeper than the stock coil, depending on the site.
When I first got it, it drove me nuts and I put it on the shelf for a few months. It's tough to use since it is quite sensitive in somewhat trashy environments, it seems to false more than the stock on deep iron or screwcaps, especially in wet ground. But that's more than an annoyance, once you get used to it. Pinpointing is tough due to the size, but doable.
I would say that depending on the site you have, you could realize anywhere from 2-3 inches of improved target ID compared to the stock, which I think in the biggest advantage of the WOT. It will ID deep fringe targets more accurately than the stock coil.
I had a spot that held quite a few deep coins (6-8inch range), and after I pounded away with stock coil, I took the WOT off the shelf and tried again. The spot literally opened up again and I dug a bunch more coins. Some were deep, 8inches to 10inches, but some were in the same range that the stock missed.
I think that using the WOT is site specific for using it's advantages. There has to be deep stuff there to find, and I don't believe that all sites have stuff at the 10in or greater range. Some of my oldest sites have nothing, at least that I can ID, deeper than 6in. Using the WOT there gives you no advantage, and probably is not the best choice. But if you have a spot that your finding targets on the fringe of the stock coils range, not overly trashy, the WOT will be able to clean up more stuff!
Dream