Does reading the Qur'an from the Mushaf differ from reciting it by heart for a memorizer of the Qur'an?

If the reciter is a Hafiz (memorizer of the Quran) and proficient, he may recite from memory or from the Mushaf (Quranic text). It is preferable to recite from the Mushaf if he can combine looking [at the text] with contemplation. Otherwise, it is better to recite from memory to devote himself to contemplation, unless he needs the Mushaf due to a weak memory.