well, I'll try..
pinenut, really, I am impressed. 
I got my Bandido II µMax today but the guy forgot to ship the lower rod with the machine. Maybe you can give me some pointers on this machine?
Pretty simple to use. My two favorite coils are the 5.75" and 8" concentrics, and I keep one of each on two different Bandidos. I was using the 8" when I found the rings yesterday, but would have grabbed the 5.75 if I were doing inside a campground.
Start off setting your threshold to a low, steady hum. I usually set mine up with disc a bit before where a nickel breaks up, and I use a spent .22 shell to do that.. .22 shells are one of my most common trash targets, and they're gone before nickels. On my Bandido with the 8" coil on it most of the time, that point is right about on "5". On my other that always wears the 5.75" coil, it's just a tad past "4".
If your common trash target is nails, set disc to where the nails break up, but aren't completely gone. Just so you know what they are and how they sound (scratchy, popping, clicky), is all the disc you want. Where to run disc is always a compromise, based on your most common (despised) trash and what you're not willing to miss. I don't want to give up nickels or gold rings, so as low as I can go before nickels, usually works out.
From there I'll "power balance" a bit negative (a
little chirpy when bobbing coil in disc), with sensitivity about "10". After a few swings I'll know if I can turn sensitivity up a tad more (usually to about middle of the red zone), and then readjust GB as needed. These Bandidos seem to be happy with sensitivity fairly high, as long as mineralization isn't too bad. I notice on the newer Tesoros though (Outlaw and Vaquero), that target response can be degraded running sensitivity too high.
If I get into an area with lots of hot rocks, I have to both lower sensitivity and run a
little more positive on the GB setting. In those spots, lowering sensitivity seems the best thing to do, as you don't want to get too positive on GB. If you're not sure they're hot rocks, switch over to all-metal and check; hot rocks I encounter are "cold" hot rocks, and null when sweeping in all-metal, though give a prolonged but smooth beep in disc..
In other places with deep pine needles (low mineralization), I can go a bit more negative on GB and bump the sensitivity higher into the red..
Seems that the Bandido II μmax likes about a medium sweep speed, though it's not to fussy if you go a bit faster, hear a chirp and slow down to check it again. Too fast and you may miss targets though. It's not quite as quick as the Vaquero and Tejon, which I think tolerate a faster swing.
If I'm in a fairly clean area, I'll run it in fast retune all-metal and listen for targets, then toggle over to disc and check. I really don't use the no-motion AM function.
I probably should do as Monte recommends and run minimal disc...but I hate digging .22 shells. I do end up digging the bigger shells though, and usually pulltabs, bullet lead, etc. I can often tell pulltabs by their harsher sound, but not always; the deeper, small ones can sound like coins. Bottlecaps will usually just "click" where I set the disc before nickel, so if I hear 'em at all, I still know not to dig 'em. With my disc set before nickels, I'm probably getting all the small gold rings (and bigger ones), though likely missing the tiny ones. Only way to get it all, is set disc really low and dig it all... Disc before nickels, seems like a happy medium to me.
Not sure if I helped much, but that's how I run mine.
