I had an '87 and liked the ride quality. If it had fit, a keeper for sure, Columbus SLX.
norskagent's '89 OS appeared to be just a great ride; he seemed to wear it, not ride it, so I'd say that's a good one.
I have had the PDG OS Series in 2, 3, and 7. Some won't like this, but the Series 7 rode as well as almost any bike I've had.
No experience whatsoever before '87.