As long as what you use is fully compatible with a wet clutch, it's not exactly an earth shaking decision. You are basically lubricating a chain and cooling a clutch (highly simplified explanation of course). As for the compensator, I seriously doubt it will make a difference what lube anyone uses. Lube choice can't fix lousy design and materials.
Personally, I use ATF. My rationale for making the change many years ago was that the other stuff I'd tried over the years always seemed to cause some clutch drag, and the one fluid definitely formulated to work well with wet clutches is ATF. And in this case theory was proved out the first time I tried the ATF. My clutch actually releases fully even after cold starts.
As for the arguments that it's not heavy duty enough for a Harley primary, consider if you will that ATF is used in 4X4 transfer cases as well as transmissions, and in vehicles with vastly more power than a Harley. If it's good enough for a two ton muscle car putting out 500 plus horsepower, I'm guessing it will be good enough for a Harley.
Jerry