Do you use Grails in your project?

As an experiment, I recently converted a web application that I wrote 2 years ago from Struts to Grails.

Some of the immediate rewards:

1. Code size is reduced significantly, especially codes that populate the beans with request parameters. Less code means easier to debug and read.
   
2. I can specify all the constraints in the entity class and don't have to create another XML file for validation purpose.
3. Taglib is very easy to write in Grails. I practically got rid of 80% of the Java scriptlets by using taglibs. My JSPs (GSPs actually) are much easier to read now.
   
4. It runs on standard web container. I have tested it on JBoss, Geronimo and Glassfish. No problem.

Are you using Grails in your project? If yes, what makes you decide on it? If no, what are the concerns?