This is a piece of very solid precision German engineering. Aligning the adjustable clamps to choose a paper folding style requires care; also, for some settings it may be the case that the clamp position must be slightly different than the position on the alignment rules on the folding plates. However, once that position is found it is reproducible, so if you record the position, setting the machine up again should take a minute or two. To find the position, send through one piece of paper at a time, and move the clamp on the side giving difficulty a half a division or so at a time until the correct position is found. Then record the position.
Loading paper while the machine is operating does not work. In loading paper, there is a tendency for the paper end inserted into the machine to ride up; being sure that has not occurred will prevent jams.
In thousands of pages, making C and Z folds, I lose well under 1% of copies to misfolds.
Note that the back plate fits in both directions; 'right-angle lip out' is correct for many folds.
Definitely worth the money if you have a fair amount of folding to finish.
Note that there is an essentially identical folding machine from Dahle at the same price.