I recently bought a bgn rz67 (and a bgn toyo 45aii--big spender!) from keh. The rz67 arrived in better condition than the toyo, with one knob showing major brassing but the rest is in essentially excellent condition. Functionally, it seems perfect, with the occasional weird quirk but nothing so far that isn't likely ascribed to user error.
I love the rz67, but may have to sell it to finance the ridiculous expense of shooting large format. I've never used the rb67, though.
I can post some photos tomorrow if you want to see what a keh bgn camera looks like. I imagine every camera from keh is different, though--luck of the draw.
Of the three lenses I have (110mm f2.8; 65mm f4 m-la; 50mm f4.5 uld), the 65mm is the sharpest and the only lens for which a direct optical corollary is available for the rb67 (the 65mm kl). That said, the 110mm is impressive wide open and the 50mm is no slouch, either: wonderful corner to corner, but still not quite as sharp as the 65mm, though it's very, very close.
I really like the rz67 and recommend it if you keep shooting film, but I imagine the value of the rz67 and its lenses will only continue to plummet, sad thought it makes me to admit it. And if I had the money of course I'd prefer a Hasselblad for its smaller size and super cool Ziess lenses, but I don't have the money.