I have dealt with Spectrasonics over years with there fine Drum software RMX now they have come up with an amazing Bass module of sounds, the Chapman stick and fretless blew me away, go to this link and in the column 2nd one down they display, select electric demo's this is way worth listening to
http://tinyurl.com/yfdknry the attack and control of the sound is purely amazing, crank it up