I've played this beastie, a few years ago now. It's interesting, but be warned -- you'll just about need to be a gorilla to hit the low notes on the fretless neck. I'm near six feet, and I couldn't hit the notes below the G on the E string or the B-flat on the A string.
It's also interesting in that there is a nice radius on the fretless fingerboard, but the baritone fingerboard is flat.
Dave O'H