I turn off all spell-check squiggles and automatic word-replacement options. If I'm using something like OPen Office, I do keep suggestions on for long words. It doesn't discriminate and if I type a long name [even a made-up one] enough it will suggest the whole word and I can press enter instead of typing it out, letting my fingers keep up with my brain. If the suggestion doesn't match what I want to write, I can just keep typing and it will go away and not change anything. If I keep spell-check on, it slows me down. That is for the editing process.