I have always felt that students can learn more from good scholars than from from professors who are not good scholars. "Can" is the operative word here. This ties in with my post some months ago in which I said I would rather have a boring teacher who is well read and a great scholar than an animated-show-person teacher who is not as well informed and knows little more than what he or she teaches in the classroom. The idea was that the sky is the limit with Mr. Boring and Mr. Dynamic is good for an hour.
An interesting new addition to the scholars-as-teachers discussion is Benjamin Barton's article on the correlation between measures of scholarship and teaching as evaluated by students. I am sympathetic to the view that scholarship by law professors is overrated which I believe is the subtext of his article. As I wrote once before, 7200 articles a year, to what end? But, likewise, what does knowing the correlation between scholarship and student evaluations tell us? If numbers of articles and citations are not measures of whether one is a scholar and teaching evaluations by students are not measures of teaching effectiveness, I am not sure I understand what I am to conclude from the effort. On the other hand, I am equally unsure of how to design a study that would get at the issue of scholars, as defined here, as teachers. In any case, I've never assumed that the most prolific writers are better at anything other than writing things down.