Does this coil actually give more depth? Would it be worth the investment in order to get deeper? I used my sniper today for the 2nd time and did pretty good (for me) with it, digging up 11 coins. None of them were any further down than about 3 or 4 inches though and I'm wondering what I may have missed further down. I do like the sniper as I get a lot of hits with it and pinpointing seems to be a lot easier. It's just a question of depth. I see the coil with the new 350 is advertised as going deeper and wider than previous coils but from what I've been able to find, it's not available for the 250 model.