I'm love instant code completion, but in my WebStorm 6.02 it doesn't works. Pop-up with options shows after few second, when I've stop typing. Need help ;-(
My Settings:
OS: Mac OS X 10.8.4
WebStorm: 6.0.2
UPD: Problem is solved by new iMac with fast CPU.
It can just be slow. If explicit Ctrl+Space is as slow, I'd suggest you to file a performance problem request to http://youtrack.jetbrains.com/ with a CPU snapshot attached (http://devnet.jetbrains.com/docs/DOC-1253).