Sometime when I type, I can see the Writer trying to second guess what word I am typing, putting a word there in highlights.
I find this just annoying and cant see how this will help anyone unless they type at snail pace.
Just a word about predictive text, or in OOo terms, AutoComplete text... I too found it annoying at first, but I discovered over time how easy it was to hit Enter when the correct word form was found. I do not type at a snail's pace. I touch-type 100 wpm with good accuracy, 130 if I'm rushing and accuracy goes down. But I also watch as I type and it's far easier to hit one key than three or four. AutoComplete saves me thousands of keystrokes per week, and I like the idea of that much less wear-and-tear on my busy hands. If the word only has one or two letters left, I just type them, no point in doing otherwise.
To each his own, of course, but i wanted to caution you not to jump to conclusions or judgments about features until after you give them a fair shake. You're not used to AutoComplete, but that doesn't mean the feature is useless.