I bought a 7230 (arrived yet) and a 6230 (will arrive soon) via Ebay for a very small amount. I was curious about the monochrome display. May be the older one even fits better to my "retro" affection in that area.
Thanks to all who answered in this thread.
One first impression of the 7230: the light is quite dark in comparison to my old 7730.
I prefer the form factor of the 7230 over the 7730.
At the moment I remove the silver color of display frame to get it all black
Nice surprise: I could use the battery of my died 7730 in the 7230.