DMM sales are always very quick to respond.
Their tech support, not so quick. There have a been a couple guys using KFlops that have had issues. One just couldn't get a drive to tune in analogue mode until he fitted their suggested mains filter, yet all the other drives were fine without the filter, and the issue moved with the drive, not the wiring.
Somebody else blew a drive up within seconds of turning it on, which was apparently due to being over-voltage, and due to them not fitting the recommended mains filter they wouldn't warranty it, yet the other drives never failed.
Plus they use capacitive encoders.

Their big advantage as you've discovered is they've specced the motors so they're far more likely to be a drop in replacement for old stepper motor systems.


Personally if cost was the main concern, I'd opt for cheap Chinese.
What tooth profile are the pulleys?