I'm thinking about buying a 15x12 s.e.f. coil for my E-trac. Does anyone else have one? I'm wondering if it gets much more depth than the stock coil. Do you think the 18x15 s.e.f. would be better? I'm leaning toward s.e.f coils because they have great target separation and accurate pinpointing. I'm also curious about the 16" Excelerator coil. Anybody use one? How do you like it? I'm curious to hear all of your thoughts and advice. Thanks