The original benchmark author is just really unclear what they're trying to benchmark. "Class vs struct performance" is meaningless, because performance at what

The original benchmark author is just really unclear what they're trying to benchmark. "Class vs struct performance" is meaningless, because performance at what? The first benchmark does nothing, as the article points out. The second benchmark tests the performance of large numbers of object creations; but why is ElementAt even being called in a loop there? It's confusing since it's irrelevant to what actually ends up taking time. If you're benchmarking the time it takes to create the struct/class objects, just write a benchmark that does that and don't include random other code! And "structs are more performant" isn't even a correct conclusion; they're pass-by-value, so you could construct benchmarks where the copy time outweighs heap memory allocation time, eg constructing a large object once and passing it to a function many times.