I personally think they are built better and shielded better too. Even on the non DST units, they make a difference in cutting out some EMI. When I had the original F75, I bought the 5" round one. The Sharp. With it, the only difference between the Fisher 5" is the weight. The Sharp is a bit heavier but approx the same depth. I just recently got the Hunter to experiment on my new machine instead of sending it back to Fisher. It is heavier than the stock coil but it does appear to be built better. My favorite so far is the Tornado coil. The 12x13 one. It's the perfect blend of weight, ground coverage, and depth. I got approximately 2.5 to 3 inches more depth over the stock coil on coin size objects. I wanted to try a different one this time around with my newest F75. I got the next size up coil...the Storm. It is 13x14. So far...it's heavier than the Tornado but I've not seen much gain over it to justify the weight. I would much rather have the Tornado as of right now.