Taperlock HTD -vs- AT5 with setscrew

I have ballscrews with plain 12 mm journals (no flat, no keyway) and I need to attach timing pulleys. The two types of pulleys that seem to be available are AT5 pulleys with a setscrew and HTD5M pulleys with taperlock. Would you get the HTD taperlocks or would you file a flat and use the AT5 style?

The screws are ground and fully preloaded. Torque will be limited to about 1 Nm.

My concerns are 1) intrinsic backlash of HTD profile (there seem to be wildly opposing views on the suitability of HTD for accurate positioning) and 2) longevity of using only a setscrew to attach the pulley.

I do have quite some HTD5 around the shop, but i do not have AT5, so can not help much.
The only thing i know about HTD5, they are for use in low vibration applications and can handle some torque.

The AT profile is probably optimal; it's supposedly optimised for low/zero backlash. The question is what is most likely to cause problems on a mill: a taperlocked HTD pulley (possibly backlash from the HTD profile?) or a zero-backlash AT5 pulley attached using only a setscrew on a filed flat?

Edit: That is, if I could find AT5 pulleys with taperlock then I would get that, but alas...

I would never use a std setscrew on a shaft unless it had a brass pad, as otherwise it always seems to damage the shaft and makes removal difficult. In contrast, if you can find a suitable Taperlock, it doesn't require a key or set screw and doesn't damage the shaft.

Many of the off the shelf pulleys are machined from lengths of toothed stock from China. I ended up making my own HTD3 pulleys after giving up trying to procure OTS pulleys with the correct tooth profile, due to the loose fit with the belt. That loose fit was translating into fairly significant backlash between the motor and axis.

Muzzer wrote:

Wow, if that's the amount of backlash one gets with HTD then that is out of the question for sure! Great illustration - thanks!

I do not think it is from the type of pulley/belt, it is probably due to bad pulley or belt teeth.
I have some mounted on a non finished mill, HTD5, no backlash at all. But i am using belts and pulleys yanked out of old machines.