Info for You
ALright, the piezo works very well especially with frettless. I don't have a fretless or piezo on my Sterling though. Some poeple actually only play off of the piezo. This apperantly is because It makes it more acustic sounding, and a little punchier. I say, if u like fretless, don't even think twice about the piezo, good luck with it, and congratulations if you do get it. But, I have a Sterling, and if youre going a little more for tha jazz sound, i say, heck why not go Sterling Fretless piezo, that's my take on ur situation.
Hope this helps, it's just some info i looked up and found 4 ya.