[msgilligan]

It would be interesting to see the results for Grails 2.2 (which uses Groovy 2 and Invoke Dynamic)

One of the nice things about Grails is that you can easily drop down to the Spring and/or JVM level when needed for performance.

[don_draper]

Yup. I manage a Grails app where I wanted to speed up performance on a popular part of the app. So I replace the Grails controller with a servlet. I saw a bump in performance.