I have seen Vishnu Sahasranama holding strong and lead role in Vaishnavas. In reality keeping aside the sections of Hinduism, how powerful is that stotra reciting daily? What is the powerful knowledge hidden in it?
How much powerful any Stotra is and what it does when read is known from the Phalasruti of that particular Stotra.
Now, there are more than one Vishnu Sahsranama Stotras. So, we need to check each of the Phalasrutis.
For example, one such Stotra is found in Skanda Purana's Avanti Khanda.
The ending verses from the Phalasruti say this:
Naamnaam Sahasram Naamedam Vishnortulatejasah,
Sarva Siddhi karam Kaamyam Punyam Hariharatmakam/
Yah Pathethpratruddhya Shuchi bhutva Samaahitah,
Yaschedam Shrunuyannityam Naro Nischala Maanasah,
Trisandhyam Shraddhayah yuktah Sarva Paapapaih Pramuchyatey/
The above Vishnu Sahasranaama bestows all kinds of ‘Siddhis’ and fulfills all desires. Those who read or hear the ‘Stotra’ with concentration and earnestness during Three Sandhyas a day would for certain become free from past and present sins. After reading the Stotra, a Devotee should recite: Sahasraakshah Sahasraanghrih Sahasravadanojjvalah, Sahasranaamanthaakshah Sahasrabhuja the Namaha
So, you now have an idea regarding how much powerful the Stotra is and what benefits are obtained by those who recite it daily.
Similarly, from the Phalasruti of the Vishnu Sahasranama Stotra that is found in Padma Purana we find:
Vishnu Sahasra naama Stotram is a sure means of ‘Paapa Vimochana’. It clears all difficulties; enhances quality of Life; keeps conscience clean; fulfills desires; keeps away poverty, diseases, and natural disasters; secures from thieves, snakes, cruel animals and evil spirits; brings in recognition and name; accords the Punya of Yagna, Tapa, Daana, Vrata and Tirtha Yatras; and finally acts as a unique ladder to Salvation
So, in this way we need to check what the Phalasrutis of the various Stotras say.