Yes indeed.. this is an interesting topic. I've found this article which I found explains quite well:
http://www.ymba.org/BWF/bwf72.htm47) Buddha Recitation -- Essence and Practice
There are two aspects to Buddha Recitation -- essence and practice. According to Elder Master Ou-I:
"Buddha Recitation-practice" means believing that there is a Western Pure Land and a Lord Buddha named Amitabha, but not yet realizing that "this Mind makes Buddha, this Mind is Buddha." It consists of resolutely seeking rebirth in the Pure Land and reciting as earnestly as a lost child longing for his mother, never forgetting her for a single moment.
"Buddha Recitation-essence," on the other hand, means believing and understanding that Lord Amitabha Buddha of the West inherently exists in full within our mind, is created by our mind, and making this sacred name -- inherently existing in full within our mind and created by our mind -- the focus of our recitation, without a moment of neglect."
In other words, "Buddha Recitation-practice" is the method of those who do not understand anything about meaning or essence, who just believe that there is a Land of Ultimate Bliss and a Buddha named Amitabha, and who fervently and earnestly recite the Buddha's name seeking rebirth there.
"Buddha Recitation-essence" is the method of those who practice in an identical manner, but who also deeply realize that the Pure Land and Lord Amitabha Buddha are all in the True Mind, manifested by the pure virtues of the True Mind.
This being so, is there a difference between Buddha Recitation-practice and Buddha Recitation-essence? Of course there is. Those who follow Buddha Recitation-practice see Amitabha Buddha as outside the Mind; therefore, opposing marks of subject-object still exist. Thus, such practice is not yet all-encompassing and complete.
Those who practice Buddha Recitation-essence thoroughly understand the True Mind and therefore sever all marks of subject-object -- to recite is Buddha, to recite is Mind, reconciling Mind and Realm.[62]Let me relate an anecdote. One night, a Master who is a friend of this author dreamed that a yellow-robed monk came to ask him, "You practice Buddha Recitation, but what is Buddha?" Answer "Buddha is Mind." The monk continued, "How about explaining to me what you mean by Buddha is Mind?" In his dream, the author's friend improvised the following stanzas:
Each utterance of the Buddha's name following the rosary is Mind,
Buddha is clearly Mind, why waste time searching for Him?
The Buddha's sea of wisdom reconciles Mind and Realm!
Mind and Buddha are born equal.
To abandon Mind and follow the Buddha is to be still in a dream,
To be attached to the Buddha as Mind is not yet perfect comprehension;
Mind and Buddha are both originally illusory and dreamlike,
To transcend both Buddha and Mind is to arrive at the perfect City of Lights.The Master understood the essence of Buddha Recitation, reconciling the Buddha's name with the realm of the Mind.
There is one erroneous idea, prevalent among those who lean toward the subtle and the mysterious, which requires clarification. Many of them, emphasizing theory over practice, tend to be attached to the concept of "Amitabha as the Self-Nature, Pure Land as Mind-Only," and reject the existence of the Western Pure Land or rebirth there. These individuals explain the sutra teachings on Pure Land from the viewpoint of principle or essence, saying "Amitabha is our Buddha Nature, the Pure Land is the pure realm of the Mind, why seek it on the outside?" This is the great mistake of those who emphasize mundane, conventional reasoning.
They cling to theory (essence) while neglecting practice, prefer essence to marks, and rely on Ultimate Truth to reject the manifestations of mundane truth -- failing to realize that the two are inseparable.[63]
According to the Treatise on the Awakening of the Faith, the True Mind has two aspects: essence and marks. The aspect of essence is called the Door of True Thusness, the aspect of marks is the Door of Birth and Death. True Thusness is inseparable from Birth and Death; Birth and Death are True Thusness. This is why the Patriarch Asvaghosha called True Thusness the "truth-like Emptiness treasury" and Birth and Death the "truth-like Non-Emptiness treasury." True Thusness and Birth and death have the same truth-like nature.
Take the great ocean as an example. We cannot accept sea water but not waves. If we were to do so, we would be wrong about the manifestations of the ocean and fail to understand truly what the ocean is. Therefore, when we abandon phenomena, noumenon cannot stand by itself; when we reject marks, essence cannot remain stable.
A great many individuals, educated in mundane ways, become afflicted with the disease of grasping at the "Truth of Emptiness" when they study Mahayana sutras, particularly those that expound the Prajna Paramita truth, which they do not fully understand. Thus, they explain sutras which elucidate phenomena and marks, such as the Pure Land Sutras or the Ksitigarbha (Earth Store Bodhisattva) Sutra, from the viewpoint of noumenon and principle. They mistake these "marks" sutras as expedients to guide those of limited capacities. However, in truth, they are the mistaken ones! In this connection, I will quote a few passages from the sutras, to destroy this attachment to Emptiness.
As stated in the Heart Sutra:
There is no wisdom, and there is no attainment whatsoever. Because there is nothing to be attained, a Bodhisattva relying on Prajnaparamita has no obstruction in his mind. Because there is no obstruction he has no fear, and he passes far beyond all confused imaginations and reaches ultimate Nirvana. The Buddhas in the past, present and future, also, by relying on the Prajnaparamita, "have" attained Supreme Enlightenment. (Sutra Translation Committee of the United States and Canada, The Buddhist Liturgy p. 47)At first, Buddha Sakyamuni, in accord with Ultimate Truth, said "there is no attainment whatsoever." Then, in accord with conventional truth, He said "the Buddhas in the past, present and future have attained Supreme Enlightenment." Seeing "attainment" is attachment to existence. Seeing "non-attainment" is to err in the direction of attachment to emptiness. Therefore, cultivators should thoroughly understand the deep meaning behind the sutras and enter the Middle Way.
In the Diamond Sutra, Sakyamuni Buddha stated:
Who sees Me by form,
Who seeks Me in sound,
Perverted are his footsteps upon the Way;
For he cannot perceive the Tathagata.
(A. F. Price, tr. "The Diamond Sutra," p. 65. In The Diamond Sutra & The Sutra of Hui Neng.)However, the Lord Buddha then continued:
Subhuti, do not think the opposite either that when the Tathagata attained Supreme Enlightenment it was not by means of his possession of the thirty-two marks of physical excellence. Do not think that. Should you think that, then when you begin the practice of seeking to attain supreme enlightenment you would think that all systems of phenomena and all conceptions about phenomena are to be cut off and rejected [thus falling into nihilism]. Do not think that. And why? Because when a disciple practices seeking to attain supreme enlightenment, he should neither grasp after such arbitrary conceptions of phenomena nor reject them. (Wai-tao, tr., "The Diamond Sutra," in Goddard, ea., A Buddhist Bible, p. 103-4.)