I've tried both and the precision bass has a comfier, less cramped neck and plays better chordally, I prefer the sound of a P too if it has a high output, whether using rounds or flats. I won't lie I'd love a Fender Jazz fretless but only for the bridge pickup tone and because the playing angle is different, its still worse chordally - for me anyway. A fretless precision is too much of a stretch.