It kind of blew me away that it could separate slightly better. And the coverage going from a 9x11 to a 10.5x14.5 felt a heck of a lot bigger than 3.5". Sure, that's only like 31% more, but it feels like I find about 2x the stuff.
I think the hardest part about making the switch from the Stock AT to the NEL Hunter, and then onto the NEL Thunder WAS the arm strength required. It was not quite so bad the Stock to the Hunter (which is only 1.5" more) but the separation was INCREDIBLE with the NEL coil I literally pulled a gold off a rebar in a park I'd hit probably a dozen times previously. I know the ring was there, because it was 5" down, literally sitting within a half-inch of the rebar. Little thing, too just 2.4 grams. The AT Pro bounced the signal enough with the Hunter that I could pick it off. It was like my 3rd hunt with the Hunter, and I was sold at that point. Went home and did some tests, and the DD coil is no slouch on the NEL.
I do have to say, it was a BEAST of a change from the Hunter to the Thunder. Quite a bit of extra weight. Arm hurt every time I went out for the first few trips. Felt like I'd picked up a detector for the first time. The thing was, I was finding so much more that the intially reduced times
When I looked at the NEL Thunder vs. the NEL Big, the extra .5 inches of length wasn't worth the extra weight on top of it. Plus, the BIG is wider (more circular), making it just a touch harder to clip edges of things, like tot-lot concrete.
if you do make the switch, be prepared to spend a couple of months working up the arm strength to run the Thunder... but at that point, the world is yours. When you're talking about the difference between four hours of hunting and 6 hours of hunting to cover a soccer field, in a two week period, I can cover 3 fields for every 2 that I used to do. The find rate goes up accordingly. Plus, the signal quality is high enough (better than the NEL BIG) that I still pick up tiny stuff.
And when I say "tiny stuff," I really mean TINY stuff. I pulled a pin-head sized metal button out of a tot-lot two days ago. 52-53 signal. Took about twice as long to find it with the pin pointer than I expected, and probably only did, because it stuck to my glove. I couldn't believe the coil hit on it. I've found plenty of earrings, but never considered just how small the coil could really detect. (Ground balance at 92).
Amazing coils.