Recently I turned to Grails and delivered several projects with it. When developing with Grails you can use the power and the expressiveness of Groovy to write compact, elegant, fluent and readable code.
The downside is that Grails is huge:
- even the most simple Grails apps will weigh in the 40MB range
- compilation, test and building takes a long time (minutes, actually) even in recent versions
- it is (fairly) complex, but that I can understand because it does so much
- it will consume a huge chunk of you app server memory when deployed
I have been using Grails as the backend for Mappu too, initially just because I wanted to bootstrap the project quickly and Grails is simply perfect for that. But as time passed I started to find Grails too heavy for a simple REST API. I am currently running the demo on the smallest Rackspace server and it's constantly swapping. It's not slow, but it could be better.