The signal a coin spill/stack can be really squirrelly, one that nobody else would ever dig or investigate..grab a handful of change and try it out, stack up differrent denominations and even the same denominations and see how wild the signal can get! Stacks and Spills are like Waffle House hash browns, they come Scatterred, Smothered, and Covered! One old guy told me to "dig 1000 pennys, and dig 1000 pulltabs" when I first got started. It was great advice! I found (and returned) 3 class rings my first year out. More importantly, I got to learn the language of the machine...try a setting and stay with it for a while, especially the tones, some like 3H, or 4H, I like DP, (you really have to concentrate to hear the low tone nickles,) so I can see why Zeek and a few others on here use the 3H or 4H, especially for coin shooting. But really stay with it for a while, like a few months! Id say also if you are hunting fresh drops, or shallow 5" targets, your target recovery speed will be the trick to the whole deal...try to get as fast as possible from the second you hit a target, to getting it up and out. After a while you'll be able to "hear" how deep a target is and what it is most likely to be based upon the sound. You wont even look at the screen much anymore, You can really cruise along in a sports field, looking for "the lane"..once you find the lane, you can slow down and harvest. You should be able to get @150 targets in a few hours...lots of them will be zippers, grommets, pulltabs, if you are gunning for gold. Heck, sometimes just walk the lane identifying the amount and types of targets there, listen intently for something just a little bit differrent than the usual, then turn around and verify by digging..look for patterns of human behavior that pay off in any particular location, theres always a sweet spot there.
Mud
ps. no luck for me on the snow, it didn't get deep, and didn't stay long, back to the dirt!