Just because it's been so quiet around here...a quick update.
I recently replaced the PLA gears on one of my Tantillus machines with Taulman nylon (actually, one set is 'Bridge' and the other is 910). This was really a test to see how it would sound/perform. The result was considerably less noise, the nylon doesn't 'clack' like the PLA. (I've also got ABS gears on another Tantillus...louder than nylon, more quiet than PLA.)
With the noise somewhat under control, I pushed the print speed up to 200 mm/sec. The motors are driven by 24 volts rather than the stock 12 volt supply, so YMMV. But, for now it's printing fast, clean and quiet.
Yes, the nylon gears had to be printed on another machine with a higher extruder temp as I haven't retrofitted an E3D nozzle onto a Tantillus. Yet.
I would enjoy hearing about others still printing with or building Tantillus machines.