Vlad, I always love your inputs.
The OP's question is a Chevy vs Ford question. How tolerant and patient does he care to be ? Because there's actually some CW hunters who, believe it or not, are using high powered pulse machines (like the Minelab nugget machines), that can get a bullet or button or coin to 1.5 ft. or more. And TRUST ME : You "won't miss a thing" when hunting with one of those, eh ? You can cut any type ground minerals, eh ? You'll go deeper than any wimpy discriminator, eh ?
But the devil is in the details: Those may be fine for certain sites. But heaven-help-the-person who goes to certain other sites, that might be riddles with nails, birdshot, etc.... Those machines will "ring the bells of notre dame" off every single pushpin and staple and paperclip. You would be wishing you had a machine that discriminates.
Some CW sites might be a function of iron-see through (various 2-filter machines that tend to see through/around iron better). Like @ firepits, or burned down buildings, etc... Where depth is not so-much the issue, as iron-see-through is.
In other CW sites (wide open fields that aren't too junky), perhaps raw depth is the objective. And another factor is: How well worked is the site ? If you're the first one to find a camp or site, perhaps just the standard coin machine (Explorer, CZ6, Sovereign, various whites or garretts, etc...) will be just fine. To quickly get the conductors out. Versus if you're Johnny-come-lately, you might need more whistles and bells to eek anything more out.
And to simply suggest a machine, is heavily dependent on the skill of the user. For example, I tend to kick the butt of many, even in hard-worked sites where raw depth is needed, with a simple Explorer II. But that's because I'm super in tune with it. Put in the hands of others, they may not find anything but shallow clad, as they don't understand the subtle tonal nuances.
So it's a Ford vs Chevy question.