Abu Hamza related that he said to Ibn `Abbas (R), "I am indeed quick i my recitation; verily, I read the [entire] Qur'an in three [days], to which Ibn `Abbas rejoined, "For me to read Al-Baqara in one night, but to contemplate it and recite it clearly and slowly is more beloved to me than for me to recite the recitation you described." In another narration, he (R) said, "If there is no way except for you to do as you said, then read it with a recitation in which your ears hear and your heart comprehends."

[Ibn Katheer: Fadaa'il Al-Qur'an pg. 236]

Imam Ahmad said, "I like smooth, flowing recitation, and I dislike speed (and hastiness) in recitation." On another occasion, when he was asked about a fast-paced recitation of the Qur'an, Imam Ahmad sadi that he disliked it, except if one's speech pattern in general is such that he cannot go slower. He was also asked if one sins by reciting with a fast-pace. He said, "As for it being a sin, I dare not go that far (he said this because he was careful and knew the sin of saying that something is Haram - forbidden - when it isn't)."

Question: Which is better for the reciter - to recite slowly and contemplate what he is reciting or to recite quickly but without reciting negligently, i.e., without doing injustice  to the pronunciation of words and letters (the one who does injustice to them is discussed above)?

Answer: With the condition that quick reading does not involve any negligence in one's recitation some scholars have ruled that it is better to read quickly, because one can recite more, which means a greater reward. Other scholars maintain that it is better to read slowly and deliberately.

Ibn Hajar said, :a Scholarly review of the issue points to virtue in both aquick reading and a slow, deliberate reading, just as the one who reads quickly does not do injustice to the letters, vowels, stops, and compulsory elements [of recitation]. There is nothing to prevent one from deeming either of them to be superior or both to be equal. A person who reads slowly and deliberately is like one who gives a single, caluable jewel in charity. One who reads quickly, on the other hand, is like one who gives many jewels, which are equal in value to the other person's single jewel, in charity. It may be, though, that the price of the single jewel is more valuable than all of the jewels that the second person gave; or the opposite might hold true."

[Fathul-Baree (8/707)]