I've come from a Java background to node.js and have enjoyed it. I'd tried a few Java frameworks for web development (Grails to a large extent and lift/spring to a small extent) but was never really happy with them. I dabbled with RoR but found it too alien. I've got no criticism to level at RoR it just didn't feel right to me, possibly if I'd continued I'd either have a strong opinion about why it's wrong or would have learned to love it. Eventually I picked up node and really enjoyed using it to develop my latest site and will probably continue to use it in future if I can and if it makes sense. I'd recommend it to any dev looking for something to new to try out.