I'm going to nitpick a couple points here.

"There is considerable psychological variance between dog breeds: in 1982-2006, there were 1,110 dog attacks in the US that were attributable to pit bull terriers, but only one attributable to Border collies"

Though pit bull terriers are indeed much more dangerous than collies, it may not be entirely behavioral genetics. Unlike collies, pits are often trained to be aggressive. Pits are also simply much stronger and more resistant to pain than than collies, so their attacks are more difficult to defend against, and thus more likely to cause injury, and thus more likely to be reported.

"A larger population means there's more genetic variance: mutations that had previously occurred every 10,000 years or so were now showing up every 400 years. "

True, but a larger population also means that "genetic sweeps" would take longer, especially given our relatively long life spans. If agricultural humans evolved more rapidly I'd say it was more likely due to new selection pressures that their hunter-gatherer ancestors didn't have.

I said progress was stagnant, not regressing.

I'm not necessarily trying to conivince you of anything, just interested. Assuming that you are convinced that Bayesian statistics are the correct way to treat uncertainty, would you say that the field of statistics never regressed in that respect because the works of Bayes and Laplace were always around?

All of Darwin's books have always been widely available and read, so no information was ever lost.

That's a pretty good argument for reading the work of the old masters though, isn't it? (Not that you voiced any disagreement with that)

Still, if the field has actually regressed between Darwin and mid 20th century (by today's standards) without evolutionary biologists of that time being aware of that fact that's evidence that progress in evolutionary biology is not necessarily clear, and reason enough to at least consider the possibility that the field might have regressed in other ways that we are not aware of.

Progress in the last 50 years is a non sequitur response to a claim that the situation was dire 50 years ago. At least, if you claim to disagree.

I don't just mean punctuated equilibrium.
Darwin wrote more than Origin and did talk about sexual selection.

I agree that an interested amateur should read the modern textbook over Origin. It's not THAT good. If you can only read one book in a discipline it should pretty much always be a textbook unless the discipline is totally dysfunctional.

Likewise, much in Darwin is part of contemporary evolutionary theory but was virtually unknown by evolutionary biologists half a century ago.

I disagree with the statement that evolutionary biology isn't making clear progress. I'm guessing you're talking about punctuated equilibrium, which was part of Darwin's On the Origin of Species (albeit not by that name), deemphasized by later evolutionary biologists, and later assertively brought back by Gould et al. However, this hypothesis is only vacillating in and out of 'style' because it 1) has scientific merit and 2) is difficult to prove. Other aspects of Darwin's theory have been easier to validate or disprove and so have been retained or decisively refuted over the years. On the whole modern evolutionists have a vastly more complete understanding of their subject than Darwin did. The entire new fields of genetics and molecular biology have opened up since Darwin's day, expanding on Darwin's theory as well as explaining the mechanics that underlie it.

Ultimately one has to look at the empirical question of the relative per-capita intellectual impressiveness of people who study only condensations and people who study original works. To me, the latter looks much much greater in most fields, OK, in every field that I can quickly think of except for astronomy.

Who says derivative works are always condensations? To continue with the Darwin example, On the Origin of Species was a seminal work, to be sure, but it doesn't explain many necessary modern concepts, such as sexual selection, kin selection, silent mutations, genetic drift, etc. If you are an evolutionary biologist then you should clearly read On the Origin of Species, among other things. But if you are an interested amateur and only have time to read one book then you should read a modern evolution textbook, in the same way you would read a modern medical textbook instead of one written in the 19th century. The old texts would contain some discredited concepts and be missing a lot of substantiated ones.