I've created a new command handler that is faster than the standard AggregateAnnotationCommandHandler.
It uses ASM to dynamically generate invokers that using direct method invocation instead of reflection.
I've included a benchmark that compares the performance.
Note about the performance, replacing the standard UUID generator with FastUUIDIdentifierFactory yield much better performance.
The entire modules has been committed to my fork here
It currently does not support callbacks, and aggregate lookup with version.
My application doesn't need them so let me know if you do and I will add it.
Next I will apply the same technique to speedup event handling.