Smaller coils are more sensitive to small gold jewelery. Small gold jewelry intended definition is women/girls rings or smaller, such as chains, earrings and pendants. Concentric coils have a "cone shaped" search area. DD coils a somewhat of a straight down "putty knife" search area. You can see basically how a DD coil works by folding a piece of paper in half and then stand it on end. That is the shape of signal of the DD coil. DD coils can "cut" through moderate to highly mineralized soil better. The 5X8 DD coil is a workhorse and does well in MOST situations. It is sensitive to small gold and separates targets well. The Super Sniper coil is a 4 1/2" concentric coil and is extremely sensitive to small gold. It also is the coil preferred by many when detecting around playground equipment, park benches, and many other obstacles found at parks and schools. The Sniper coil is useful for target separation, sacrificing depth for target identification at those sites that are heavily infested with aluminum foil, pulltabs and bottle caps and other assorted unwanted targets. I personally have found gold jewelry with each. It's really not about which coil picks up gold better, it is about having the correct coil for the correct site application you are hunting. Some will say just go with the 5X8 coil, some will say why would a person take a chance on missing a gold by not having the correct coil. It is definitely is not a one size fits all when it comes to searching for lost gold jewelry. The choice is yours to make. Good luck and happy hunting.