This is my second set of fluence pickups: I also have a guitar with the fluence moderns, so that's going to be my main point of comparison. I put this set into an Les Paul style guitar, so I actually followed the Fluence Classics wiring diagram, with a PP pot for each tone knob, one switching from voice 1 to voice 2, and the second switching from humbucker to single coil mode. So to be clear, there are four distinct sounds available for each position - voice 1 humbucker, voice 1 single coil, voice 2 humbucker, voice 2 single coil.
Compared to the moderns, the bridge pickup in voice 1 humbucker under distortion sounds quite similar, maybe ever-so-slightly less tight in the bass, but all very much in the realm of an EMG 81-type sound. Where I hear a much more distinct difference is playing clean on the neck pickup. Unlike the modern, which has so much treble that they included the HF Tilt wiring to chop off those high frequencies when needed, the Devy set is inherently much more controlled, and in fact, voice 2 single coil actually feels darker to my ear than voice 1 single coil, with less high frequencies despite being lower output, even in single coil mode. Also, interestingly, switching between the voices has, to my ear, a much more dramatic effect on the overall tone than switching to single coil mode, which you wouldn't expect, especially as you can get some 60 cycle hum with enough gain when you go to single coil. Finally, compared to the moderns, the Devin Townsend set seemed to me to have noticeably overall higher output - I found myself needing to position the pickups lower to prevent from clipping on my interface.
For me, there are some specific instances where I actually like having the option of those very high frequencies in the moderns, even for clean neck pickup sounds, but for those who wouldn't wire up the HF tilt, or generally find the moderns too bright, might find the Devy set much more balanced. I think this is where people find them more "natural" or "organic" or "passive sounding" than the moderns, even though the sound is, to me, still very much that of an active pickup. In short, I really like them as I do fishman fluence pickups in general.