I really like mine. My only complaint is it has about an 8" depth cutoff. I mean it has a door slammed at that depth. I've used it side by side with my CZ's and with other guys who are using ETracs, Whites, etc. and have been tuned out of targets that were within the ranges of those other rigs.
I've kept it running full on all out for the most part, and it ID's great to that magic door. After that, it usually won't even see a target settings be damned. The exception being the lowly beer can or large iron fixture.
I have not tried the bigger or smaller elliptical coils. I use the 5" DD and the stock 11" DD. Depth for both of these coils seems fairly close as I've dug many 7" targets with the small coil including small targets.
Do a lot of sidewalk tearups and I cannot use the 11" coil in those environments, the cinder, ash or EMF from noisy overhead lines seems to turn it into a chatter box unless the thresh is at +5 or better but the small coil rocks in those places.
So I don't sound like a one note organ, Saturday I was walking through an old farmfield on the way to an old site and turned it on, the 11" DD coil on. Got a great barber quarter tilted about 6" deep that rang up clear as a bell in the glacial mix and thick sediment of the field. There is a lot of ground mineralization in most such sites from a huge combination of variables including the glacial drift, farm chemicals, the long gone and now liberally spread bits of barbed wire fencing, etc...
Got two silver geos also that day with the rig, one at 2" and the other almost 7", both rang up the same and pinpointed dead on. Between the Feq options (Hz button) and the thresh settings you can usually get this machine operational almost anywhere with nearly max sense, and with the small coil on that makes it a great tool for noisy ground, trashy parks, demo sites and the like.
Using the larger DD coil and following that prescription the unit is fit for pretty much any open ground application as well including older sites. I really look forward to picking up the bigger elliptical coil one of these days and also trying that big 15" DD coil, once it's been proven out by others.
The down sides I've found were as Sandman states, my application and settings in pretty much all cases. A little crosstalk problem with some ETracs and as usual, most Garret machines but just break your buddies' rigs if they make too much noise and it's all good. If you can't break their rigs, tell them to change their channel settings or hit their noise cancel and it should clear up right away.
