Nothing is faster for me when opening gargantuan text files. It's never broken for me and never lagged either. I think that's pretty impressive, not to mention the customizability options.
Not to mention if you hit ctrl-f and search for something in the file. Another lock-up for a few minutes while it tries to figure out highlighting. This is something I've reported to them. I have never considered Sublime to be a good handler of large files.