IDE's are a nuisance, but what's a bigger problem is your typical framework that will include a few hundred classes and a few thousand methods and properties.

Keeping that all in your head is a serious effort, especially if you don't work on the same project all the time.

I try very hard to stay away from IDEs and environments that require one to function, but 'modern' looking websites and applications more or less require the use of such frameworks.

So I find myself using the documentation probably more frequently than I really need to, in order to simply look up the names of stuff and I probably am not using the frameworks to their fullest potential because I can only memorize a subsection of them.

Even a 'lightweight' framework can easily come to 100 classes.

So, my toolset: vi + my memory, but it's tough going.