We ran into some GWT compilation issues mainly due to code size a couple of times with some browsers, like Safari, that left us dead in the water until Google released an update.

The second project used vanilla GWT and we were very happy with how performant it was. But we avoided lots of GWT features which seem over-engineered and complicated. We used JSON overlay types instead of RPC calls (which made our compilation / or dev mode much faster - I forget honestly). We avoided MVP, because I never met anyone who actually fully understood MVP with GWT. Instead, we had a very simple MVC structure that worked great for us (but lacked unit tests..). We avoided most of the CSS features because the complexity/value wasn't favorable for us.

Moved on to a JS project afterwards and it was a breath of fresh air.

But comparing a functional scripting language with a object-oriented statically-typed pre-compiled language, arguing one is better than the other, does not make sense to me.

You can easily revert the situation and say that static typing is a weakness of java, and it's poor fucntional (until before v8) capability is a drawback and a strong point for Javascript.

I'm not into the JS world so I can't say anything about the tooling, but yes, Java's tooling and ecosystem is an extremely strong point.

My complaint is about dismissing Javascript as not a "real language" while it's got A LOT going for it.

EDIT: I also worked with GWT (GXT from ExtJs, actually) in 2011-2012, and it was really nice. I miss it.

GWT can output to ExtJS, to <insert next HTML5/JS framework>, to <future platform>. And barring minor changes, your code stays the same.

Now that is worth the investment.