Recently it has been brought up on the mailing list that some users are seeing poor performance: https://mail.openjdk.java.net/pipermail/panama-dev/2019-May/005445.html

After some bench marking with it turned out that most of the overhead was coming from the struct getter, and the field getter paths.

There is still room to improve the perf of these paths, e.g. by specializing the getter MethodHandle per struct class, and reducing the number of actions needed to create a Pointer for a field.