When I was learning C++, it was conveyed that structs were more for combining like data that didn't necessarily require a class because it had a bit less overhead. An example would be a lot of variables that are related, but have no methods (such as a creating a node data structure for making an implementation of a linked list or tree).
Though the above was related to C++, that's generally when I use structs for C# as well.
I think a real world use case for structs is for avoiding allocating objects in performance critical code [1] - though I'm not sure it is required in the vast majority of code.
Very misleading title. It should be called "My personal opinions on top mistakes that C# programmers make". There's otherwise, no data, no study, no reference on what's actually the top mistakes that C# programmers make.
On a separate note I much prefer the lambda style Linq to the SQL style. I think it easier to work with, but I'm not sure why.
With regard to classes versus structs. I rarely use structs. What are the real world use cases for them over classes?