I feel to be a good typist one would have to have a good grasp of reading, grammar, and the ability to make errors to a lesser degree than moreso.
I can type, myself, 120-150 wpm with an error rate of 0-2. I also have the ability of not having to look at the keyboard as I type, and have a good eye on catching errors. My grammar is not as good as my spelling (in such regard as to punctuation, and structure) but a good eye is always a key in being a good/great typist.
This is the field in which I wish to get into in the future; not right now, however. But, later.