Hi Dan. Gear drives would always be my first choice, but unfortunately the "new" normal at Harley isn't conducive to using gear drives unless you also true the flywheel assembly and provide a means to keep it from shifting. The absolute maximum pinion shaft runout S&S allows is .003", and as I noted in that other thread it's best to be no more than .002" for best results.
People might remember that not all that long ago Big Twins came stock with gear driven cams. I find it enlightening that using older designs, older materials, older tooling, and older methods, Harley was able to make gear drives work. Now with supposedly better design, materials,and tooling, they can't produce a crank that's precise enough to run gear drives. But they can crank them out in higher volume with lower quality at lower cost, and that seems to be the strategy they've embraced. With a rapidly changing market that includes a fading Boomer generation and increased competition, that strategy won't be sustainable IMHO. Eventually people get pizzed off and refuse to pay more for less.
Jerry