Not to mention you write "obj." and can instantly see all the methods available with arguments.

Also if you add say an interface or inherit a new object it will immediately throw an error if required methods are not implemented. You then just hit ctrl+1 and enter and it will automatically add all the boilerplate functions you need to comply with the new interface.

It's a must for statically compiled, boilerplate filled languages like Java and C#. That said, if intellij is more polished for a niche and has a better UI I'll switch away from Eclipse in a heartbeat.

If you're not working with a dynamically typed language or markup language though then an IDE can really add a significant boost to productivity by eliminating all the repetition and actually making the strict static typing work for you.