> #2 Ruby forces you to learn "the ruby way". For folks who are only used to java, seeing ruby code is like...seeing another language.<p>This is hardly a point of difference between any 2 languages/frameworks.
These points seem trivial and obvious. I would be much more curious to see performance comparisons, congruent external packages (what is the 'devise' analog in groovy) and how might your solution to the same problem differ in each framework.
A few notes:<p>Grails db migrations will be bundled as standard in grails 1.4 (hopefully released in next month or so). Currently it's a plugin - grails install-plugin db-migrations.<p>Reloading - this is something that happens a lot to the Grails' domain reliance on Hibernate. I was told some time ago that it was being worked on to be more seamless, possibly requiring fewer/no restarts. FWIW, in dev mode, controller and view files are automatically reloaded without requiring a restart. Service files with static methods in them seem to require a restart, and domain changes require a restart. If you change a domain, in dev mode, the system will restart automatically, but it'll go through the init process, and your state will be lost.<p>Testing - conceptually there's a lot of nice stuff in Grails, but Rails is still further ahead here due to speed. Grails <i>unit</i> tests are generally fast, but <i>integration</i> tests require the whole Grails stack to be started, and this generally takes 35-45 seconds on my system (MBP 2.66ghz). You can rewrite a lot of integration tests as unit tests with loads of mocks and such, but it's not elegant. Grails 1.4 is supposed to bring 'improved testing', but I'm not sure what that means.<p>If you're doing groovy or grails, you owe it to yourself to use <a href="http://kobo.github.com/groovyserv/" rel="nofollow">http://kobo.github.com/groovyserv/</a> which starts a daemon. Running groovy normally invokes a JVM on each command - groovyserv eliminates that entirely.<p>Finally - gentle plug - if you're in to groovy/grails tech and haven't checked out groovymag.com PDFs, please check it out. Ping me for coupon codes if you want. :)