I don't think Kant's approach to religion is any longer viable in its original form. But that does not mean it is simply wrong or that we cannot learn from it.

If the problem of free will is to see how freedom fits into the order of nature, then Kant's basic view about the free will problem is that it is insoluble.

Kant can provide, and has provided, a good model for philosophers to think about the relation of metaphysics to science and scientific methodology.

Capitalism has not proven to be a transitional form, a gateway to a higher human future.

People are often most proud of precisely those things of which they should most be ashamed.

Our decisions need not be seen as resting on procedures that are merely instrumental in making judgments that are reliably truth-tracking. The procedures might be more directly related than that to truths about what is right or good, or about what we ought to do, or to principles that tell us what is true about these matters. And I have no metaphysical theory about the truth-conditions of such truths, except to say that as objective truths, they must be independent of the attitudes, decisions or actions that they are supposed to justify or for which they are to offer reasons.

I think that both Mill and Sidgwick are great and admirable philosophers, from whom we still have a lot to learn. I would not favor a form of Kantianism (if there is such a form) that treats Mill's or Sidgwick's moral philosophy with disrespect.