I fully agree with the original posters sentiments.
We are a Java + Spring shop and took the opportunity to try out Grails.
We first created a very small test application which turned out to be pretty simple to do and it worked pretty well. The main issues we had here were due to our lack of knowledge with Groovy and Grails.
Following this success (confidence boost) we decided we would attempt a slightly larger project. This has been a much more painful experience. As mentioned by others, we have uncovered all sorts of bugs and issues which were not immediately apparent on the surface. The app restart cycles get extremely painful and unless you have really good test coverage its a nightmare to do any sort of re-factoring.
Really frustrating is having code fail without a single error message! It just does not work and you don't know why?
I like the ease of use of plugins for JMS, Quartz and Remoting to name a few. Does away with a lot of tedious XML.
I almost like GORM for its simplicity though we have had several issues as well.
I don't like the loosely typed nature of Groovy and the fact that you have to run your application just to be able to catch a bunch of errors, reminds me too much of PHP or Rails.
At the end of the day we are asking ourselves if its possible to write a complex piece of manageable software using Grails...
We have a Grails application about to go into production....so we will see.