I use my Joey when I hunt trashy areas, more often than my X-5. Because I get great target separation, and a larger footprint. Note that I still use the X-5 when it is a REALY saturated lot.
The Joey also excels in the field where you have items to dodge around while looking, i.e., a forest, or planted field. It performs quite well in those conditions. Easier to slide in and out of areas between plants. Of course, be mindful of the DD formation because you want to put the target passing perpendicular to the long side.
My thoughts on the depth loss.....it is minor, but so what? You are ALWAYS going to have targets deeper than your coil can reach, and though we all look at an "average" of X years equals Y depth for a given target, it is not always so. I have found coins from the early 1800's at 3 inches, and conversely, I have found 25 year old coins at depth. For my thoughts, I don't select my coil on just how deep, but it is good practice to use different coils, based upon target separation and target types. I use a WOT, 15x12 SEF, 8x6 SEF, X-5, 8 inch minelab, and a stock coil, as well as my Joey.
If you are thinking on getting one, by all means get it. You will most definitely be using it at times, and being able to snake it around in close quarters is great.
It is NOT touted as being water proof, and so , be aware of that. And, it has a coil cover taped on, or at least mine did. So clean that out and replace the tan coil cover tape with some electrical tape. Mine is Yellow tape. No reason, but it does look different now. I thought of putting some silicone caulk to seal it, but what if I miss a spot. I have plenty of other coils that are water proof, so I just hunt up to damp and wet grass, but I don't submerge it in water.
The only other thing I would say, is that on ALL of my coils I sprung for an extra lower stem, so I don't have to change the nut and bolt out. In the field, it is a quick changeout for me. And they fit nicely in a backpack if in the woods. Except for the 15x12 SEF It does not, but I still have it pre-attached to a lower stem.
HH
Dennis