I've had mine for about six years. Previous ones were Teknetics CZ-7a Pro and CZ-70; Garrett GTP-1350, Garrett AT3 Beach Hunter; and Teknetics Gamma 6000.
Right now my two units are the GTI-2500 and the Teknetics Omega 8000 Version 6.
Hands down, the GTI2500 surpasses all the others I've used. It's just as sensitive as any of those others. The Target Imaging makes the difference.
With the other detectors, it takes more swings over the target trying to figure out its size. A target that's "fairly large and deep" can look like one that's "small and shallow". They can get fooled by a 4-inch piece of slaw at 8-9 inches, that pinpoints similarly to a coin at 3-4 inches.
... (I know some folks will dispute that, saying that it's just a matter of expertise and experience and "knowing" your detector.)
During pinpointing, the GTI2500's automatic Target Imaging shows you what you've got. Not just "depth". It shows "depth" and "size" also.
Not to pound this too hard, but please let me go on with it just a bit more.
I have compared the GTI2500 -- pinpointing -- directly against an AT Pro and an Equinox 600 (belonging to other guys), as well as with my own Gamma and Omega. With the GTI2500 showing a coin-size target at 4 inches, that's what you dig. You see it up front, before digging.
With the non-imaging detectors you might have a coin at 4 inches, maybe not. Sometimes you've already dug deeper than that -- say, 7 or 8 inches -- and your pinpointer still shows a larger target deeper down in the hole. Keep digging? Maybe it's a good target down at 8 inches, maybe trash. But why did that other detector show a shallow coin? You always have to decide ... keep digging this hole, or move on and cover more ground.
The point is, with the Target Imaging, you can dig a deep hole for a larger target if that's what you want to do. But you won't be digging a deep hole and still wondering why the smaller target hasn't come up yet. You see in advance both the depth and size, and it's pretty darn accurate.
Another good GTI2500 feature is the continuous, automatic, ground balancing. It keeps balancing while you're moving along, swinging your coil. You can do manual tweaks if you like. I've found the automatic balancing to be accurate.
Those other detectors have been good, just missing one feature. They've been fun to swing with. But after using the Target Imaging for awhile, I wouldn't want to do serious detecting without it.
This has been a long post, and it's just one person's opinion. I apologize if it's rubbed anyone the wrong way.
Cheers,
Joe