I recently read Brian Leiter's The State of the Vocation and found I liked the argument. There's a caveat to that. I'm not really sure I understand what Leiter means by "vocation." To my ear, or eye, as the case may be, the word suggests something contrary to what it seems to express for Leiter; not membership in a profession but a calling extending well beyond the confines of one's job or career. I think he means "profession," but given that he uses several different forms of the word "profession," I would have thought it would leap to mind, so I keep wondering if there's some special reason for using the word "vocation." But it does have something to do with jobs and careers, which keep coming up. The Weber quotation is supposed to clarify this; but Weber, I had thought, used the word "vocation" in much the sense in which I'm inclined to take the word: it had to do not with professional work but with intoxicating, obsessive passion that motivates hard self-discipline; in the paragraph Leiter quotes, he is talking about the state of the vocation of science under the hand of the 'devil', i.e., rigid rationalism, and what Leiter seems to take as the characteristics of science as a vocation, Weber takes as the unavoidable facts that limit the vocational character of science. (So I would have interpreted it; it is possible that I have misunderstood Weber, since I find the line of thought in the lecture hard to follow.) This fits with some of what Leiter says, but not all. Because of that I'm not sure I really understand Leiter's meaning, and I find the conclusions about vocation a bit mysterious; it's the perpetual problem of differing idiolects.
I'm also inclined to raise a skeptical eyebrow at the argument for the importance of rankings. I'm really not surprised, of course, that Leiter makes it, but I do find the appeal to Collins unexpected and interesting. I would suggest, however, that if we are building on Collins, Collins's work on stagnation also suggests that things like rankings are really a symptom of a problem the profession is currently struggling to overcome (and for which it has no clear solution in hand), namely, massive, and steadily increasing, fragmentation and dilution of talent. (It could, perhaps, be argued that they are a temporary solution to certain aspects of this problem.) Collins's work can be read as showing that professionalization in philosophy breeds reaction against the profession, leading to the marginalization of the professional aspect of philosophy in the major philosophical work of the time, which is eventually drawn back into the profession when conditions change. What we think of as the major philosophical work in the early part of the early modern period, for instance, is closely connected to a major series of attacks on the philosophical profession of the time; philosophy moves out of academia and stays out until academics in places like Scotland and Prussia begin doing some heavy reworking of university institutions and conventions. Then, very slowly, philosophy begins moving back into academic life and taking on more of the features of a profession. In our day this has become very advanced; and Collins has argued in a number of places that academia in general has begun to show the signs of entering into a phase of stagnation -- prime breeding ground for the beginning of an anti-profession counter-reaction. The good news, if Collins is right, is that philosophy can survive quite well outside a professional context; the bad news, if he is right, is that the old bogey, which was once upon a time called the 'philosophy of the schools' or the 'the philosophy of the schoolmen', may return to haunt people as the symbol of intellectual stagnation and triviality -- and, if so, we would be the ones being labeled with it (not quite fairly, now as then, but fairness is not really in view in a reaction of this sort). It's also possible, of course, that Collins is wrong.
Regardless, rankings and job placement information really don't tell us much about networks, which in this day and age are not likely to be confined to single departments -- indeed, never really have been. Networks involve interactions along lines of interest. Philosophical interaction within departments tends to be much, much less than interaction within, say, philosophical societies and associations. However important the department may be, the institutions that primarily support the creative interactions of academic networks today are conferences and journals. Departments have a value in this primarily when they do two things: produce new members of the profession and support members of departments to make it easier to engage in network interaction. The sort of department ranking that would genuinely be useful for network analysis is ranking of departments according to how well they perform their supporting function. It's very possible that rankings like those in the PGR are indirect measures of this, but we have do not at present have a good way of saying how indirect, nor do we seem to have a clear way of linking them to the sort of network interactions that dominate the field.
But when I say I like the argument in Leiter's piece, though, I mean that I like the approach he takes for these mysterious conclusions, namely, a serious regard for the institutional, conventional, and social character of philosophy, a recognition that to understand philosophy here and now we need to look at networks, institutions, hierarchies, and the like. We need to have more of this sort of examination of philosophical practice today.