You can see a lot of what I have gone through to get my Maslow setup here
The Maslow M that I did, didn’t appear to have any repeatability issues at all. Coming from aerospace machining I was very impressed with this home assembled machine! I am working on my second piece now and it is 42” top to bottom and three passes with an 1/8” bit looked to be repeating themselves very precisely. That said, I need to add more weight for keeping the loose chain ends under tension because I did have them wrap around the drive pulley and dig my bit through ply at roughly 10mm depth of cut. All appear to be well and the bit even returned to center so no harm no foul I suppose. I didn’t find calibration to be as much of a nightmare as I expected, although it does take paying attention to a fair number of things. I was moving along a 650mm/min (25.6ipm) with an 1/8” 2 flute bit and it was working like a charm with a .100” depth of cut. I’m sure I can cut faster though, or take a bit deeper cut. I would imagine that it would save you time on things you need done repeatedly, but for me my time is eaten up trying to get my head around FreeCAD. Good luck!