It's true that there is a lot of painfully bad epistemology in feminist discourse. However, the proportion of bad epistemology is typical of most human discourse concerned with advocacy. Theorists concerned with advocacy often fail to work according to the following dictum:

First make a dispassionate and disinterested effort to figure out whether X is true. Then worry about whether it is right or wrong to assert X.

That said, I think that I've benefited from reading feminist theory. I think that I sympathize with its claims more often than most people. Reading feminists helps me to overcome the Typical Mind fallacy. For example, the "put myself in a woman's shoes" heuristic wouldn't be enough to make me realize how uncomfortable some women are with being propositioned by an undesirable person in an elevator.

Also, I'm struck by the extent to which feminism and PUA theorists provide independent confirmation for each other. They often join each other in opposition to the conventional wisdom. For example, feminists and, say, PUAs of the Roissy variety will agree that some innocuous-seeming action is intended to infantilize women. The feminists and Roissy just disagree about whether it is right to act that way with that intent. They agree about the "is" claim; they just disagree about the "ought" implications. I typically side with the feminists on the "ought" questions in these cases, but I can appreciate the PUAs for corroborating the underlying "is" claim.