Sorry for side-jacking this comment - but which version of Sublime, may I ask, and what OS?

I'm using Sublime 2 on OS X and large files + regular expressions are generally a cause for pain.

Do you have any default settings changed like disabled document preview or similar?

The only thing I generally feel is a champ at regular expressions + insanely large files on OS X is TextWrangler/BBEdit. In fact, I keep TextWrangler around specifically for the large file excellence experience which I (currently) don't receive on Sublime Text 2.