Deviations
The major alteration in the fact  of the story found in the Adhyatma Ramayana is the introduction of a  "Shadow Sita" throughout the period of her abduction. The real Sita  disappears into fire just before the golden deer episode. Tulasidasa also  follows the Adhyatma Ramayana in this respect.

Compare Tulasi’s Sri  Ramacharitamanasa, Aranya Kanda, Doha 23 and the Chopai: "When Lakshmana  had gone to the woods to gather roots, fruits and bulbs, Sri Rama, the very  incarnation of compassion and joy, spoke with a smile to Janak’s daughter  (Sita):- Listen my darling, who have been staunch in the holy vow of fidelity  to me and are so virtuous in conduct: I am going to act a lovely human part.  Abide in fire until I have completed the destruction of the demons."

"No sooner had Sri Rama told  Her everything in detail than she impressed the image of the Lord’s feet on Her  heart and entered into the fire, leaving with Him only a shadow of Hers, though  precisely of the same appearance and the same amiable and gentle disposition.  Lakshmana, too, did not know the secret of what the Lord had done behind the  curtain."

In the Adhyatma Ramayana, Sita  emerges from the fire at the end of the war when the shadow Sita enters into  it. (The whole drama is preplanned and enacted at the bidding of Sri Rama  Himself).

Other alterations in the Adhyatma  Ramayana include: Ravana treats Sita with the respect due to a mother and Sri  Rama establishes a Sivalinga at the site of the bridge to Lanka.

The major contribution of the  Adhyatma Ramayana lies in the casting of Rama in the role of the spiritual  teacher and in the several exquisite hymns sung in praise of Rama. There are  four occasions when Rama assumes the role of the teacher and gives  philosophical disquisition.

Rama reveals himself as  four-handed Mahavishnu at his very birth, a feature that is not seen in Valmiki

Sage Valmiki depicts Sri.Rama as  an ideal man while admitting his divinity, whereas Sage Vyasa present him as  the Supreme Being incarnate with the full remembrance of his divinity and the  recognition of it by all wise men.

In response to Lakshmana’s  questions on different occasions he teaches knowledge, devotion and detachment,  methods of worship and the way of emancipation. In reply to Kaushalya’s query,  Rama teaches the three Yogas of Karma (action), Jnana (knowledge) and Bhakti  (devotion).

The well known Ramagita is part  of Adhyatma Ramayana. It contains teachings on Advaita Vedanta. The real  contribution of this work is in its repeatedly propounding the doctrine that  Rama is Brahman the Absolute and that Sita is His Maya-shakti or Prakriti,  thereby raising the personality of Rama to the highest level and providing a  firm base to the worship of Rama.

Ahalya the wife of Sage Gautama  is in invisible form in the Valmiki Ramayana, whereas in the Adhyatma she has  been depicted in the rock form.

In the Ayodhya Kanda of Adhyatma  Ramayana the section opens with a visit of Sage Narada to Sri. Rama to remind  him of the purpose of his incarnation, which Sri. Rama acknowledges. All these  incidents are not in Valmiki.

In the Adhyatma, banishment of  Sri Rama is accomplished by the Devas through Goddess Saraswathi, by possessing  the two women i.e. maid servant Manthara and Kaikeyi. In Valmiki this incident  is explained as a simple court intrigue.

Sage Valmiki’s evil past has been  explained in detail in Adhyatma, but not in the other.

In Adhyatma, Lakshmana requests  Rama to instruct him on the means of attaining Salvation. Rama also gives him  an elaborate discourse on Jnana and Bhakti, conveying the quintessence of  Vedanta. This is not there in Valmiki Text.

According to Adhyatma, Ravana is  aware of the fact that Sri. Rama in human form is Lord Vishnu incarnated to  kill him. Ravana is also aware of the fact that destruction at Sri. Rama’s hand  is easier way of gaining salvation than through spiritual practices (devotion  through confrontation - an example for vidvesha bhakti).

In Adhyatma - unknown to  Lakshmana, Rama informs Sita that Ravana will be  coming to abduct her, and that therefore he is  handing her over to the Fire  deity Agni  for safe custody, till he takes her back again. In her place Maya Sita is left  in Asrama, and it is this illusory Sita that Ravana abducts. This is unknown in  the Valmiki.

In Valmiki, it is Kabandha who  advises Sri. Rama to make friends with Sugreeva and gives details about the  place of his residence, whereas in Adhyatma it is ascetic Sabari who first  tells Rama about Sugreeva and informs him that Sita is confined in Ravana’s  palace.

After the death of Vali it is  Hanuman who consoles Tara in Adhyatma Ramayana, whereas in Valmiki Sri. Rama  gives her an elaborate advice of philosophy of Vedanta and the practice of  devotion, besides consoling her.

In Adhyatma while Rama is staying  at Mount Pravarshana after the coronation of Sugreeva, he gives an elaborate  discourse to Lakshmana on the ritualistic worship of Lord Maha Vishnu (i.e  Himself), thus revealing his identity with the Supreme Being openly.

Swayamprabha comes to meet Rama  and praises Him, identifying him as Supreme Being. According to the advice of  Rama she goes to Badari to attain Mukthi..  This episode is absent in Valmiki.

Sampati gives an elaborate  discourse to the monkeys who meet him He quotes Sage Chandramas, while telling  about the divinity of Sri. Rama. This incident is available in Adhyatma only.

A conspicuous addition in the  Adhyatma is Rama’s installation of the Sivalinga in Rameswara, before the  construction of Sethu for the success of the enterprise. Rama also declares  about the merit of Pilgrimage to Rameswara and Sethu Bandha here. These elaborations  are not available in Valmiki.

Sri Rama is well aware of his  divinity during the Nagapasa missile episode and Garuda’s arrival to release  them. In Valmiki, Rama is not aware of his Divinity till the end when Brahma  imparts that knowledge to him.

Kalanemi obstructs Hanuman while  he is on his way to bring Mritasanjivani, a herb that can revive one who is  almost dead. This incident is absent in Valmiki.
   
Narada praises Rama after the  death of Kumbakarna in Adhyatma. This is absent in Valmiki.

Killing of Maya Sita by Indrajit  and illusion created thereon by black magic is available in Valmiki but not in  Adhyatma

Before going to battle Ravana,  for gaining invincibility in fighting, begins fire rite, as per the advice of  his guru Sukra. This rite is blocked and stopped by the monkeys. These  incidents are absent in Valmiki Ramayana.

Rama cuts down the heads of  Ravana repeatedly, but could not kill him.  Vibhishana informs Rama that Ravana has got  amrita deposited in his umbilicus and that until it is removed he cannot be  killed. This is available in Adhyatma Ramayana. But in Valmiki Ramayana as per  the advice of Sage Agasthya Rama chants Adhithya Hrudaya and worships Lord  Soorya to kill Ravana.

According to Adhyatma on the  death of Ravana, his spirit, having luminosity of lighting enters into Rama and  attains salvation. This explanation finds no place in Valmiki.

After the death of Ravana, Sita’s  fire ordeal is only to replace the Maya Sita by Rama. The whole event is given  the appearance of a real ordeal in Valmiki.

In Adhyatma Ramayana every one  praises and chants the hymn on Rama  starting from Vamadeva, Valmiki, Bharadwaja,  Narada, Viradha, Sarabanga,  Sutikshna, Agasthya,  Viswamitra, Vasishta, Jatayu, Kabhanda, Sabari, Swayamprabha, Parasurama, Vibhishana,  Hanuman etc. This is absent in Valmiki.

Conclusion
Though the traditional origin of  these two Ramayanas are different and though there are differences in the  treatment of the subject - Rama Katha - one should not jump to the conclusion  that there are contradictions between the two. We have to bear in mind that  both of them deal with the same history of Rama and what Adhyatma Ramayana has  done is only to make explicit what Valmiki has taught us implicitly and  indirectly in his epic. As a much smaller text (containing about 4000 slokas)  than that Vamiki’s (containing 24000 slokas) and complete in itself, Adhyatma  Ramayana offers the devotees of Rama a smaller and devotional exposition of  Rama’s greatness which they can use in their daily practices of worship.

Jai Shri Ram

References:
1. Adhyatma       Ramayana by Swami Tapasyananda
2. Kalyana       Kalpataru - Srimadadhyatma Ramayana Number - October 1998  and
3. Adhyatma       Ramayan (Hindi) - Both by Gita Press, Gorakhpur

Also read
1. Life of Sant Tuslidas
2. Travel to Chitrakoot closely associated with Shri Ram