Richter tuned harmonica a semitone higher, following the principle of a chromatic harmonica tuning. So essentially, what you have in your hands is a classically tuned diatonic harp with some of the possibilities of a chromatic harps and more besides. The harp plays really well compared to its cousins the Slide Harp and the Koch. Although technically that's a real feat, it is by no means sufficient indication that the instrument is perfect. They are louder of course, but that is not very audible unless you play chords.
Chords sound odd compared to unvalved chords.
On the plus side, the CX-12 design is excellent and the mouthpiece especially is very well designed and allows for the mouth to slide really easily from one side of the harp to the other. The slide is very smooth and easy to action. The thing is, don't expect to play this baby like you play a standard diatonic. It's definitely a different instrument that requires getting used to. Embouchure needs to be adjusted, attack needs to be subtly different and breathing needs to be managed differently.