First bass I had was a fretted el-cheapo, made my own fretless and truss-rod-less neck (eeek, yeah indeed) just for the fun of trying. Second bass was my beloved Peavey T-20FL, yes fretless, the one I'm married to, never left me, loads of fun. As said, after a while you change fretless for fretted without trouble. Both have their charm.
Advice: be sure to avoid looking at the fret markers whenever you feel the urge to, it'll help you refine your hearing which is imperative when playing real (no markers) fretlesss. Anyone who ever played a violin or upright knows what I'm saying.