I've had a DX-5000 in my stable for many years. It spent the last 4 years as a long term loaner / once-in-a-while commuter for my brother and he has recently returned the bike to me. While the frame is very structurally sound with absolutely zero rust, it was in dire need of a fresh coat of paint.
I have heard talk about how much chrome is actually under neath the paint job of a DX-5000. All speculation, really. I was so interested in this subject that I once emailed the guys at yellowjersey to find out more. They told me that, aside from the immediately visible chain area, there was an extra inch of chrome and that's it.
So today I began the stripping process. The chrome is clearly visible, for anyone who is interested:
So, it appears as though roughly half of the rear triangle has been dipped. Not bad, I guess. For reference, the tubing on my bike is Tange Champion 1. Panasonic also made the DX-5000 in Columbus steel. I don't know how much chrome is under that version.