Performance (ReadOnly)List vs Immutable collection types
A bit back on LinkedIn, there was a discussion about read-only collection and immutability where this is not the point I want to discuss now, as I already covered that here: "ReadOnlyCollection is not an immutable collection".
This post is just about the performance of those types compared to our baseline, the good old
List<T>. It also explains why we see the results we see.