This is a new 4 string fretless model with the 3 band upgrade (2 band is standard). Other upgrades include: translucent red finish, matching headstok and pearloid pickguard.
The pau ferro fingerboard has fret lines that will help you play in tune.
As for the sound, if you’ve ever heard Pino Palladino’s work on songs by Paul Young or Chris de Burgh (just turn the radio now and there’s a chance they are playing “The lady in Red” or “Everytime you go away”), you know how sweet and singing a fretless Musicman can be.