"So what Erwin has documented for me is that I don't need to feel left out because I can't afford a very expensive 50mm lens for my R-D 1 -- there'd be no visible benefit compared to using the lenses that I already own."
He hasn't documented that at all. As you know, lens performance includes many variables. There are indeed very visible differences among lenses on the R-D1:
http://www.luminous-landscape.com/reviews/lenses/rd-1-lens.shtml
I enjoyed Erwin's article but one can see how it feeds into a kind of mindset, that seems to have gained momentum in the last few years, regarding cameras and lenses. And the mindset is that somehow by citing numbers measuring some aspect of a camera or lens, one can describe performance generally. That's not the case.
The Canon L lenses made a big difference on even the 3.3 MP D30 - a very visible difference.
The Leica ASPH lenses are stellar performers on the R-D1, look at those corner crops again. The challenge is that they tend to be contrasty.
It aint' all about megapickles
It ain't all about resolution charts
It aint' all about MTF charts
...add your own lines as the spirit strikes you.
Sean