Bi-directional or not when ecthing

Seems to me the bigger difference is in the scan angle than in the bi-directional scan. Or in any case, I think it’s difficult to attribute the quality difference solely to bi-directional scan when you have another variable in play.

The biggest apparent difference between the two is that the one with vertical scanning has a visible gap between lines. Looks like you could optimize the interval space for a cleaner look or at least to more closely match the horizontally scanned version.