pracchannam bauddham ucyate
mayaiva kalpitam devi
"The Mayavadi philosophy is veiled Buddhism." In other words, the voidist philosophy of Buddha is more or less repeated in the Mayavadi philosophy of impersonalism, although the Mayavadi philosophy claims to be directed by the Vedic conclusions. Lord Siva, however, admits that this philosophy is manufactured by him in the age of Kali in order to mislead the atheists. "Actually the Supreme Personality of Godhead has His transcendental body," Lord Siva states. "But I describe the Supreme as impersonal. I also explain the Vedanta-sutra according to the same principles of Mayavadi philosophy."
Teachings of Lord Caitanya, Chapter 19".... Sankaracarya's belief is personal. Actually he is a covered personalist. He became impersonalist just to drive away Buddhism. All of India was Buddhist voidism. So, although a personalist, he had to keep pace with voidism by expounding impersonalism. There is very little difference between impersonalism and voidism, but because he had to bring Buddhists back to the Vedic cultural form, he adopted impersonalism. From the Padma Purana, it is learned that Sankaracarya is Lord Siva, and who can be a greater devotee than Lord Siva? Lord Siva is considered to be the foremost Vaisnava."
Srila Prabhupada Letter to Damodar, 11-12-70