As someone who recently came back to Java from a 5 year stint with Rails, I can safely say this is not true by any stretch of the imagination. If you stick to those tools in the Java ecosystem which meet your requirements, you can be incredibly productive.

The problem is that the Java world is full of over-engineered solutions which are really targeted at extremely large enterprise applications surrounded by a community of folks who like to menturbate about them. As a startup, you don't need to focus on those solutions. You'll not need 99% of them.

However, you can choose bit and pieces. I'm using Vaadin, JPA and Guice and finding it incredibly productive and am able to deliver functionality in far less time than it took me in Rails. I'm not using 90% of the Java EE stack, but it's available to me if/when I need it.

Rails was a great thing for the software development world. It drove convention over configuration and caused a lot of the competing technologies to pause and question why things were the way they were. But IMHO, managing the whole Rails stack (rails + coffeescript + css in our case) across a group of people became a chore. YMMV, but the statically-typed nature of Java along with the very capable technology stacks you can assemble have eased our daily jobs tremendously.

Do you have actual experience with developers of similar skill levels building a similar app in Spring and Rails?

While undoubtedly less expressive I think most of the bad rep Spring gets is because it's used in "Enterprise", which means programmers that are, if not of lower level, constantly interrupted and yanked around and told what not to do.

I wouldn't choose Spring anymore because there are better alternatives, but I'm pretty sure the 10x is in the programmer and not the framework. The framework might be 2x, if that, but not much more I think.

P.S. If you include Spring Roo then I'm pretty sure the 10x no longer holds, but I never got up to speed on Roo myself so I can't say anything authoritative on that.

Oh sure, there are reasons to use an easier/faster-to-develop language, I believe every developer should know a 'hard-and-fast' language and a 'slow-and-easy' language... and know when to use them.

98% of the websites out there could run on python and I doubt we'd see a big performance difference.

However, I really don't think there exists a 10x difference developing in Spring. Hell, I don't think there is a 10x difference in using Struts vs Rails.

Spring development is considered slow as it brings images of enterprise shops taking several years to go through the bureaucratic red tape necessary to incorporate a new feature.

I've worked with plenty of small companies using Spring and their development/release cycle is maybe 1/2 or 1/4 the speed of comparable 'easier-to-build' technologies, but it definitely isn't 1/10th the speed to develop.