I am debating whether it is worth the $220 for the larger imaging coil. If it easily detects a few inches deeper, then it is probably worth it. Does anyone have experience with 12.5 versus 9.5 inch coils on the Garrett GTi series?
Word on the street is the diameter of the coil should equal the depth attained...BUT I'm sure there are many variables to consider also...rain is your friend, I mean the dampness left behind...power lines are bastards with larger coils...larger coils also 'see' a lot of junk, and also have a tendency to 'miss' shallower targets. I have not used this set up, but did had a 10x14 on my Ace-250 and it was the good ,the bad and the ugly all rolled into one unit. Yes I found some deep stuff, but it was a finicky coil also...Good luck, i'd research it a bit more myself...
At a new coil option. I think I will pass. My thought was the 4.5 sniper over the larger 12.5 which would be cool on some of my larger private properties. I'm going to stay with my stock 9.5 with Sun Ray for now, until I get used to my setup. I am confident with my 10-12" depth for now on some relics.
I'm wondering where you hunt most often. I hunt mostly in parks where trash levels are high. A 5 X 8 coil helps me to isolate the good targets while working around the trash. I have often found the clay level at about 5 or 6 inches. I don't often find good targets beneath the clay line.
I would think that hunting relics and deep large targets in open fields and on farms would be where deeper targets might be found. That is where I would consider using a bigger coil. IMHO
And old ball park I've hunted before. Parks in St. Louis, we have a large park that been hunted for years it dates back 1874 the 1904 world fair was their. We have clay here too, when its dry it very hard.