Immutable collections in Java 9 – do we need them?

With the release of Java 9, we got an opportunity to elegantly create an immutable collection by using nice factory methods. But, what benefits do we get as developers with immutable collection beside getting an exception when we try to change the content of the collection? Besides this, the microbenchmarking features introduced in Java 9 will be also presented to compare the performance differences between mutable and immutable collections.