I would like to get a larger coil for my AT Pro. I have the factory 8.5"x 11" and the 5" x 8" DD coils. I love the 5"x 8" for water and trashy areas, but would like something larger for covering more area per sweep and of course better depth on land. I don't care for the how the 8.5"x 11" coil makes some trash targets sound and ID in the copper or silver range. So, is there a good 12"-13" coil that anyone has used and recommends? Either that or I'm going to go with a Etrac for parks, etc.