I'm partial to the White's DFX for my all-around machine. My DFX is at home on a salt water beach to prospecting in the mountains. The DFX has something like 12 different coils available from small 4" DD or concentric, to 18" Bigfoot coils. It's a great relic, tot lot or park machine and perhaps the best cherry picker on the market. Greatest of all is a good used one can be bought at a mid-level price even tho it competes with the high-end market.
For me a good all-around detector is above average in all categories of hunting. I think the DFX fits the bill with the features and performance of a top-of-the-line at a mid-level price.