The benefits of dynamic languages are not their speed, its the rapid prototyping and interactivity they provide once the prototype has been designed it can be implemented for speed in any lanuage providing the features you need.
Well, then I disagree that after two years of really using Python for everything, that I've been much more productive than with Java. I bet I spent a good chunk of that time debugging errors at run time which would have been caught at compile time with Java.
Of course that is a non-scientific anecdote and there are times that the REPL is just awesome (especially for web app development).
This has been my experience too. Currently I like Python for quickly banging out web apps, and Java for building the back end stuff.
Sure, Java has some baggage, but it has a lot of benefits too, such as much better tools for deployment, performance profiling, libraries galore, the JVM, and more. I find it's often the best tool for the job when there's heavy lifting to be done.
