OS X IDEA extremely sluggish autocomplete

Running 2016.2.1, build #IU-162.1447.26, I've noticed that the auto-completion suggestion list populates and updates very, very slowly as I type, introducing marked lag between keystrokes.  Is this an issue anyone else has contended with and, if so, are there any fixes?  I'm on the stable release path as far as updates are concerned.  I've found the following suggestions and implemented them with no change:

• Help > Edit Custom Properties > editor.zero.latency.typing=true

• Help > Edit Custom VM Options > added -Xmx2048m

I've also completely removed IDEA from /Applications and reinstalled fresh, to no effect.

Thanks!

Christian