I recently bought the NEL Attack 15" for my AT Pro. I knew I would be gaining some depth over the stock coil which is what I needed for the fields I hunt. Since I was in "dig everything" mode at my mom's farm, I was shocked at the crater size holes I was having to dig for a 2 inch nail. That coil was hitting tiny targets VERY deep. I have had no separation loss and I find the pin pointing to just as good as the stock coil. Also, I had heard that the 15" could get exhausting, but I didn't find that to be the case. I was able to swing it for over an hour non-stop and that is AFTER swinging the 5x8 for five hours earlier in the morning. They sell harnesses but I don't see the need for one.
Seriously, a 2 inch nail was at the bottom of this 18 inch hole. I am in love with this coil. I am a firm believer in a coil for every situation which is why I have the 5x8, the stock and the 15".
View attachment 1173124
Again, it was for the PRO but I hope the info helps.