LOL, not I. Don't get me wrong, the idea is pretty wicked, just not feasible. For the price you can easily own a killer fretted and a killer fretless bass.
If you're looking for sustain and lots of mwahhh, it's in the action. Try a nice buzzy fretless and the distance from the fingerboard to the string is MUCH lower than the distance from the string to a fret on even the nicest of fretted basses. When ya do some math on how high the strings are off the fret and also factor in the height to the fingerboard, yup, fretless with high action.
I think these basses appeal to people because there's too much fear associated with fretless basses. In my last band, I never brought a fretted bass to a gig.