Thanks, everyone, for the replies. It's been most helpful.
When I got serious about photography several years back, I did a lot of reading and research. Something that came up often was the opinion that as long as you've got a good enlarger lens, the rest of the enlarger was less important. Although the Jensen article was very biased towards condenser enlargers, it was a useful read, and certainly convinced me of the need to have a high quality, alignable condenser set. My current enlarger, an Omega B22, would appear to have no way to adjust the condensers or the lamp position.
So, it's time to upgrade. Maybe that's where those elusive steely grays and luminous highlights are hiding! 8-)