The blog post discusses the performance improvements offered by Span.SequenceEquals compared to the traditional memcmp function for comparing arrays in C#. It highlights that memcmp incurs overhead due to being an external function that cannot be inlined and involves marshaling which creates pinned memory handles. This overhead can result in slower performance when passed as marshalled arrays. Utilizing Span, specifically through stack allocation or direct pointer manipulation (using fixed statements), eliminates much of this overhead, resulting in faster comparisons. Several user comments note the importance of context when discussing performance - comparing methods like std::span in C++, questioning the extent of overhead from calling memcmp, and expressing curiosity on how modern .NET frameworks perform especially in Linux environments. Additionally, respondents acknowledge the emergence of Span as a powerful abstraction that facilitates efficient data handling in C#, praising the speed-up seen with recent .NET iterations (post .NET 6). There are also warnings about outdated information from older StackOverflow answers, indicating the fast-paced evolution of language features and techniques.