I prefer unlined - currently have four fretlesses, one lined, two unlined, one defret which doesn't have visible lines. Had to have the dots moved on the lined one so they're on the lines, I think I'll either just have to cope with the defret as it is or do what my Ibanez SRF705 has, teeny little fret markers on the edge of the fretboard. Incidentally, I have occasionally played a bass which was a fretless but was then fretted and the dots at the fret positions are really confusing, silly as it may seem.