There's been some discussion recently in the PrintNC discord about precision and repeatability of the "standard" PrintNC build, so I thought I'd throw a Dial Test Indicator at mine and see how it's looking.
This is on a "default" PrintNC with aluminium X axis roller plates but still printed Y axis roller plates. Everything else is stock, and I haven't really spent any time fiddling to try and increase precision, I've basically been sporadically abusing the machine for almost 2 years.
TLDW: Looks like I've got around 0.005mm backlash, and things are pretty repeatable to 0.01mm but not 100%. Possibly because my steps/mm is currently 160, so that's only 0.00625mm/step. I haven't tried increasing my microstepping because I haven't been chasing that high precision.