I can tell you that that's not normal. Have you ever got in touch with support?

I've just upgraded to Pycharm 2.7, it's a lot better. It also looks a lot less horrible.

However, there is still an unacceptable delay between typing and feedback, around 300ms.

Performance was clearly not a priority for them.

definitions of 'unusable' vary greatly. 16gb 2ghz quadcore 2011 mbp with 256g SSD and intellij is usable about 95% of the time - I get slow downs and hangs, but their OS-level stuff - I get the same stuff hangs in macvim, textwrangler, eclipse, pixelfari and other apps.

Unusable as it very often freezes for about 5-60secs. Only IDEs written in Java appear to suffer from this, and that's most of them.

I want a good IDE, but none of them are good.

Have you tried editing the the bin/idea.exe.vmoptions file to set -Xmx higher?