Who doesn't love those lines? That was indeed a lovely show. However, what you say reminds me that I often think we deify the old masters' overmuch. Particularly their "line" quality. It's as though no-one has ever, or ever could, make a line to equal those of the past. I don't buy that for a moment. It makes all present efforts so futile and it unrealistically mythologizes the Old Masters. Now, don't get me wrong, they aren't the old masters for nothing, and they are the giants upon whose shoulders we Lilliputians are trying to stand astride, but still ...
Do we know how many times Raphael traced over previous drawings to get at the one he eventually used or liked? Do we know anything about other aborted attempts? Maybe he didn't even like that one we saw, but it's all we have today and so we ascribe to it mythological qualities that we wouldn't were it not a "Raphael". It's so impossible to reverse engineer these things.
Finally, I'm wary of trying too hard to emulate perfectly a specific line quality, for example, from the old masters. That kind of thinking -- and I'm not saying you're doing this, Mark -- is what led to so many of the 20th century's abominations. Somehow, there developed a mentality that said all the old masters were about were certain, specific techniques and all you needed to do was emulate a certain, specific technique -- such as a line -- and you're like an old master yourself.
Juan