I always described my Gunnison as the most indestructible, reliable, and unlovable reel ever made. Where you need a disc drag, it's most always over-qualified (but then that applies to most places disc drags get used, anyway). It is useful for the by-catch of red salmon that always accompanies Alaska rainbows. Likewise, on my last Alaska trip. found a Marquis was not useful for the same under-gunned activity (fine for the rainbows).
My disc drag vote for most fishable reels goes to Valentine, both single-action and planetary - a better Medalist-on-steroids and simpler design than the Gunnison. My vote for the most esoterically pleasing disc drag (ok, drum brake drag) of all time goes to Marryat, which was the fly fishing candy of the 1980s, complicated to unequaled smoothness by an aluminum roller-bearing clutch. The most over-qualified disc drag of all time, as well as the purest simplicity of function, goes to Abel, and this is the reel you want for tarpon and blue water. Runner up for functional simplicity goes to Lamson LP (actually a caliper-brake drag), but I wouldn't pick one for a tarpon reel.
Anyone who has fished a postwar Young that I've had my hands on knows how amazingly fishable these reels can be.
Properly tuned, the click is as sweet as any Hardy, and way out-ranges any click-pawl ever designed by Hardy (which includes CFO).
My favorite innovative/fishable click-pawl designs are at surprising extremes of the spectrum. Hardy's vertical-pawl-and-crown-gear Prince. Not only is this Hardy's widest-ranging check, but the fact that it fits inside the spool arbor changes the geometry and function of the entire fly reel in a positive way. First time you put one of these on a rod you discover you've gotten used to the off-center winding and torsional imbalance created by the offset weight of any other check/drag design.
The other is the most enduring and endearing click-pawl ever - Martin's helical spring check, found on the reels we give the similes of Poor-man's CFO and Poor-man's Hardy Lightweight - and not without reason.