Del,
Any machine that has tone id that you are comfortable hunting with will do the job.
As for me personally I've gotten used to running a combo: one detector for trending and one detector for focused hunting.
For
trending, it has always been about the coil, either a Cleansweep or a Bigfoot coil. These 18"x4" coils excel at this activity as they have good response characteristics and can cover a LOT of ground in a short period of time. Since only Tesoro and Whites offer this size of coil, my trending units have always been limited to these two makes. Tesoro only has one tone id unit that works for trending and that is the Golden MicroMax. A Golden uMax with a Cleansweep coil is my all time favorite unit for trend hunts. The Cleansweep coil is also in ready supply.
The Bigfoot coil works good too, but they are now in scarce supply as Jim isn't able to supply them. A Bigfoot coil on a XLT or DFX make good trending units but I think a multi-tone Prizm and a Bigfoot coil would do better. I was going to test one out but I couldn't find a prizm bigfoot coil at the time. Still think about it though as Prizm 5 or 6T would make a good trending unit if the coil could be obtained. Right now I trend with a V3/Bigfoot combo. Still undecided about it and I'm still suffering from the sticker shock. I wrestle with the price tag every day. But the programable tones give me a few more options.....
For
focused hunting, the Fisher F5 has beat out all the others I've ever tried for this. It is nearly perfect for inland jewelry hunting. It has the right feature set. It has the sensitivity to hunt chains, the tone id modes really resonate when a positive threshold setting is used, recovery speed is excellent, and it can ground balance spot on. It has the best target id resolution from about the middle of the tab range and up that I've ever used in this frequency range. It has the notch feature needed to really focus. I love it. The 4 tone audio selection has a separate nickel range tone that just jumps right out at me that causes me to stop in my tracks. Anything that bounces into that tone, either from foil or from tab gets recovered. When I'm using the F5, good targets just seem to pop out of the ground. I still dig a fair amount of trash but it isn't enough to wear me down. You that gold hunt know what I mean. I'm not wearing out digging foil or tabs and my good target to trash ratio is better than with any of the other units I've used. I just wish I could get a Cleansweep/Bigfoot type coil for it.
One trend I've found involves a site type that also includes rebar reinforced concrete curbing. The F5's two tone VCO mode is excellent for this type of site as it can hunt right up alongside the curbing. The good targets "zip" in the midst of the rebar grunts and long falsing tones.
If I could only get a cleansweep or bigfoot type coil for the F5 I'd be in detector heaven.
Well, you asked!

Mike