When I was a PhD student at The University of Chicago, boundaries among departments were relatively fluid because (a) the interdisciplinary workshop system; (b) faculty offices were scattered through all the buildings; (c) graduate students did not have offices; (d) teaching in the college was not confined to individual departments. So, one place where philosophy students would encounter bona fide Straussians was the political theory workshop (where, for example, I met Nathan Tarcov, who taught a brilliant course on Plato's Laws). Even so, philosophy faculty and the Straussians (who were largely scattered in political science and social thought) didn't seem to mingle much. There didn't seem to be alot of outright mutual hostility either, and boundaries became ever more fluid as Philosophy appointed folk that had scholarly chops to match the Straussians (Larmore) and Social Thought appointed high powered philosophers (Lear) a few of few of which had their own Straussian roots (Pippin) or overlapping intellectual backgrounds (Marion). Graduate students certainly mingled. Even so, even philosophy faculty that had spent a near life-time at Chicago would occassionally ask me like what courses taught by Straussians were like. When Straussians moved to Washington (as Leon Kass did) talk certainly turned to the connection -- intrinsic or accidental? -- between Straussians and neo-cons. But given that Chicago's philosophy department became the home of its own petty energetic cult (with a student hierarchy and in- and outcrowd) we had our own obsessions. Of course, when Myles Burnyeat came to teach a graduate seminar on Plato's Republic, the seminar was full of students intimately familiar with Straussian commitments, and I remember a couple of terrific exchanges where somebody would note that Myles' own brilliant reading(s) had some resemblance to Bloom's.
Among the Straussians, Joseph Cropsey stood out for his warmth and generosity.
Even so, I would not be writing about Cropsey because of his teaching. Rather, I wrote my dissertation, in part, on Adam Smith. One of the great joys of that experience would be bumping into Cropsey along the Lake Shore. On week-ends he would be out waiting for my dog (a Bullmastif), and the three of us would talk about Adam Smith. In the dissertation I mostly disagreed with him on details, but I also pointed out (p. 126) the current revival of Smith as an egalitarian is in no small measure due to his 1957 book. Until Ryan Hanley's book, Cropsey's was the most important introduction to Smith's political thought. I'll let others comment on his more Straussian work on Plato (although I always admired his graceful writing style). But it is worth calling attention to an unappreciated gem: his (1955) "What is Welfare Economics?" Ethics , 65(2): 116-125. This is profoundly critical of then (relatively) new mathematical theory of welfare (as developed by Samuelson and Lerner among others). It is possible to quible with his psychologistic interpretation of the new welfare economics. Even so he points out critically that "The political consequence of [the new mathematical welfare economics]...is that the maximum satisfaction of preferences takes precedence over the maximum satisfaction of the requirements of justice as the norm of the common good." Rawls's succesful response to Arrow (and Samuelson) can be seen as a vindication of Cropsey's insight.
I share one political memory that is related to Cropsey. On the eve of an election (I believe Clinton vs Dole), Harvey Mansfield came to Chicago to give a talk, which was really a campaign speech on (I think) Dole's behalf rather than anything substantive. (I recal that Erik Curiel gave a spirited refutation from the floor during Q&A.) After the talk, Mansfield gave a more temperate seminar. During this seminar Cropsey was extremely critical of Mansfield. In particular, he spoke very movingly about having witnessed the desperate bread lines during the Great Depression. He left no doubt that blind faith in real world Capitalism could verge on the inhuman. Like Adam Smith, he was familiar with the dangers of the love of system.