Zend Studio 8 has performance problems with large php source files (around 3,000 lines of code) causing MAJOR typing lag. There has been a patch developed but apparently they haven't rolled it out yet as nothing happens when I to go Help > Check for Updates.
Is there any way I can manually update the IDE so I don't have to wait for Zend?
Since ZS8 is a commercial product and only available for a few days now, you are likely still entitled to support. Please login to the Zend website and open a support ticket. They will get back to you and likely will provide you with a patch (if there is one) and instructions on how to install it.