IMO, the article lacks a comparison to the functional elephant in the JVM room.
The improvements over Java are things addressed in (typed) clojure.
I get the feeling that comparing Ceylon to Java is like comparing a 1990s car against a 1980s car. That's not to say the comparison is invalid but if (and only if) the goal is to have/make/evaluate a good car you should compare it to 2010s cars.
But I think that I would be similarly productive in it (or perhaps less) than in Java even after let's say 1 year experience because of:
* Worse readability (parens, less regular). That's the #1 problem of Clojure.
* IDEs, including LightTable, are not even close to the usefulness of Eclipse or IDEA.
* Imperative code is easier to write and more importantly more readable in Java.
* Formattig code for readability is PITA. In Eclipse, I usually just press Ctrl+Shift+F to autoformat after every edit.
4clojure.com is fun for learning basic syntax and problem solving, but it doesn't really teach you how build applications with Clojure.
> * Worse readability (parens, less regular). That's the #1 problem of Clojure.
I have to disagree with you here. Clojure's syntax is a lot more regular than Scala's or even Java's.
> * IDEs, including LightTable, are not even close to the usefulness of Eclipse or IDEA.
You can use Eclipse or IDEA, though the support for Clojure in these IDEs is not as good as it is for Java. This is only natural because Java is a lot older and statically typed.
> * Imperative code is easier to write and more importantly more readable in Java.
Naturally imperative code is easier to write and more readable in Java, because lambdas are not yet available. If you mean Java's imperative code is more readable than Clojure's functional then I would like to know if you have an equal amount of experience in these languages?
> * Formattig code for readability is PITA. In Eclipse, I usually just press Ctrl+Shift+F to autoformat after every edit.
I don't understand your point, you can autoformat Clojure code.