GWT may not be fashionable, but the compiler and other development tools are very advanced, and big Google products use it. So I'd think twice about bashing it.
I'm not sure where you got the idea that the compiler was advanced - what it does is amazing but incredibly slow.
The development tools were fine in 2008 but they're showing their age now... the browser plugin only runs in Chrome, Firefox and IE, and it's only fast enough to be productive in Firefox. There are no browser plugins for Safari or mobile and doing a compile to a WAR can take minutes on a big project, which means development for mobile can be glacial.
I've just worked for a year on a big GWT project... it seemed like a good idea to start with but I've grown to hate it over time.
It is an extremely powerful tool, with some big caveats too, as you mentioned.