coalescent answers the question, links to other answers; and there are more in the comments.To answer the question you have to have some idea of what other readers are like. You can call yourself a fast reader if others are slower, but 'fast' isn't really an attribute in itself. The way I read seems natural to me, and I think it reflects my extrovert intuitive personality.
A casual reader. I am not bothered about the physical manifestation of information. I print out text from the computer, staple the sheets together, and then after I have read it I might leave it lying around or I might throw it away. The object doesn't matter to me. I mean, I have books, but just to get at the content.
A prickly reader. I get put off quite easily. If I perceive something I don't like behind the book I can't read it. I am aware that sometimes this reaction is too fast to be entirely rational. I am also prickly at the literary establishment. Like they care.
A hypnotised reader. Engrossed in a book I won't hear you speak. I'll answer and I haven't heard the question. Sorry.
An assertive reader. I largely trust my own judgement of the worth of what I read (a bit of a contradiction to the 'prickly' point).
A lazy reader. I don't persist enough with difficult texts, so I let myself down.
A passionate reader. Sometimes I become so excited by what I read that I can hardly contain myself.
And you?