My experience with Grails on one of my recent projects has been anywhere from frustrating to annoying!
I can’t deny the fact that Grails is a pretty powerful convention driven framework as advertised by it’s founders. It has done well to bring most of railsy philosophies and techniques into itself. It does help in accelerating your software development cycle and being AGILE to a certain extent. The programming language Groovy is pretty sound I think.
The shortcomings of the framework like lack of an enthusiatic developer community supporting it, lack of a solid testing framework(the one that it currently provides is so undocumented and feature-less), unhelpul stack traces and logging etc hit you really hard sometimes.
I d prefer Rails over Grails anytime! What do you think?