I am so glad I bought the Glarry instead going in the deep end with a Tony Franklin. I can play unlined fretless and I can stay in tune, but frankly, I don’t need the challenge of an unlined fingerboard. Lined or not, it is very easy to go out of tune playing fretless. The lines make it much easier for me to self correct. Your mileage may vary, but I have no shame in my game:we get no bonus points for difficulty of execution, so I am happy to have the help of lines.