Formal:
* Proficient typist: This emphasizes skill and accuracy.
* Skilled typist: Similar to "proficient," but less formal.
* Rapid typist: Focuses on speed.
* Adept typist: Implies both speed and accuracy.
* Efficient typist: Highlights speed and effectiveness.
Informal:
* Speed demon: A playful and informal term for someone who types incredibly fast.
* Keyboard warrior: A slightly sarcastic term, implying someone who types a lot, perhaps with a competitive or aggressive attitude.
* Flying fingers: A descriptive phrase highlighting the speed of the typing.
* Type like a madman/woman: A more casual phrase emphasizing speed.
* Fast as lightning: A hyperbole to describe someone who types very quickly.
More specific:
* Touch typist: Someone who can type without looking at the keyboard.
* Hunt-and-peck typist (but fast): A somewhat humorous way to describe someone who doesn't use all their fingers but is still very quick.
The best option will depend on the specific situation and the tone you want to convey.