I have had my CTX for the about a month now and I purchased a 6" coil to hunt in the rocky beaches when I water hunt (I am primarily a water hunter). Previously I have been water hunting with my 10" excal for large sandy beaches and my 8" excal in the rocky beaches but since my 8" excal has been sent in for repairs I have been using the CTX with the 6" coil. I have been playing around with the CTX at a couple of parks and schools to try and learn the machine better. In the last 5 water hunts and 3 park hunts, with the stock coil I only found 1 gold ring, every time I put the 6 inch coil on I have found gold or platinum. I have hunted the same beaches and parks with the 6" coil and I have pulled up 5 gold rings at the last 5 beach hunts, a gold ring and a platinum ring at my last two park hunts... When hunting the parks with the stock coil the machine recommends a sensitivity between 4-8 and I am usually able to run the sensitivity between 12-14 without it making way to much noise but even at that I can only detect a nickle at 4 inches max and it is iffy with no reading on the display, just audio. With the 6" coil the recommendation is 10-14 and I can manually get away with 19-22 and I will pick up a nickle at about 6" with a jumpy display but solid audio. The stock coil is great for dry sand hunting and but that is the only place that I think that I will use it, all other times I think that the 6" will be my go to coil.