I would suggest you try for yourself. I love the flexibility of Grails and the Development Speed. However as you can see other people's experience differs. I want to be able to develop rapid applications for my clients using the Java Platform and I have found Grails to work very well for us.
I have also found the frontend very flexible to develop. I also think you need to use common sense and choose your plugin's carefully. I stick to the plugins supported by springsource.
