I'm hunting a low mineralized dry sand beach area, with lots of rusty iron and new beer bottle caps. Recently a very experienced beach hunter told me, to use the stock concentric coil rather than the 11" DD. There is gold/silver jewelry and coins in these areas, in the soft sand sometimes it is quite deep. Will the stock concentric "hit" the good target better than with the DD? Will it see between the iron, better? How much depth would I lose by going to the stock coil?? What is your advice, stay with the 11" DD or put on the stock concentric? I was told that the stock coil is "crappy" so I have a;most never used it.......is this a mistake? Thanks for your help and advice!!