performs excellent.
The bulk of my detecting is in very dense trash, often associated with a lot of brush and even building rubble, so the round 5½" DD coil gets used most often. Especially with I'm working in and around a lot of rusty tin, or perhaps a modern-use location with a lot of crimp-on bottle caps. Those types of targets, with very challenging problem ferrous make-up that man designed in an annoying shape that enhances their conductivity and can annoy any make or model detector, seem to be better handled by the smaller-size search coils.
In many places I hunt, generally non-rural and quite often littered with a fair amount of iron debris, I like the 5½X10 Concentric coil when the area has only a modest amount of trash, and whe the iron-based problem targets are mainly nails, cut wire [size=small](such as fencing pieces)[/size], screws or similar less-offending shapes of ferrous. I also prefer the 5 ½X10 Concentric coil over the Double-D design because it provides a little better depth, but mainly more consistent Discrimination, a tighter and more accurate visual TID read-out [size=small](due to the uniform EMF on a coil approach from the left or from the right compared with the challenges caused by the overlapped Tx and Rx internal windings of a DD design)[/size].
I do have a DD coil of that same size, but I keep it mounted on my FORS Gold + most of the time for Gold Nugget Hunting with some occasional use for Relic or Coin & Jewelry Hunting applications. It is also a very good search coils for modest trash areas where you are not dealing with dense brush or building rubble. Also, I like the fact these two coils are solid designs that eliminate snagging when searching places such as stubble fields, in the woods with twigs and weedy vegetation, etc.
The 7X11 DD is a search coil I like to use when hunting in water, be it a coastal or inland saltwater or freshwater beach, or open grassy sports fields, parks, or yards, and other sparse target places. Also when I'm after larger-size targets or want/need a littler more depth than the 5½X10 coils provide, but those two elliptical solid coils work very well on the Relic.
Monte