Comments: I've got the 450B fretless that I bought second hand. The only reason I didn't give a 10 for playability is because I'm not used to playing fretless. But this bass makes it worth it. The zero fret is a nice addition, I wish all guitars and basses had zero frets.
The bass itself is solid as a rock. I noticed the body to be slightly neck-diving, but not something that gets in the way at all.
The pickups are clear, articulate, and chunky. Combined with the metal neck, I get lows I never knew existed. The bridge pickup can sometimes tend to be a little thin on some settings, so I usually roll the tone off a bit or keep the bass in the middle position.
The craft is imaculate. You can tell that Kramer really cared about these basses during their construction.
I won't be parting with this bass. It sounds like no other. It's as much about feeling the notes and the vibrations travel throughout the neck and the body as it is hearing it.