I failed the course, got an F. It was a course that prepares phd math students for their prelims but students from other programs can also take it. In undergrad, I got a B in analysis and a C in measure theory. The independent research experience I had during college, though, was in analysis. And I thoroughly enjoyed it despite my other analysis grades.
For undergrad econ classes, I took Intro (A-), Macro (B), and Resource Economics (D).
In grad school, I took two microeconomics classes (As), Econometrics (A-), and Energy Economics (A-) counted toward a public policy degree.
Let me know if you want more info. Thanks for asking questions.