Gary,
I have the Alembic strings on my fretless Epic and feel it is a really good string for an active sound with minimal fretboard wear. If you attack the string aggresively and vibrate the string across the width of the board rather than a classic wrist vibrato, you will see some wear no matter what string. I do not like the sound or lack of responsiveness of flatwounds. I really love roundwounds, but don't want rounds on my fretless. Having Said that, IMO I feel the Alembic string is a good compromise. They really do sound good for me, and have a somewhat roundwound responsiveness without the agressive wear from a true roundwound. If you lose too much top end with this string, you can always boost the Q or preamp treble to compensate.
Kris