Vaishnavism has become a cult of Hinduism in the present scenario. The organizations like ISKCON are trying to promote it for several years. However, it has done some good works like promotion of some Vedic and Indological concepts in the western world. On the other hand, Dr. Michael Creamo and some other such persons did some good works to get the evidences of Indian timeline, which goes beyond lakhs of years.
But, the biggest problem that if I find with Vaishnavism is its overlooking of Vedas. Those, who are inclined towards this culture, will find it strange, because of their prejudice that whatever is being taught in Vaishnavism is Vedic. But, if you observe the things, when it comes to giving references, it gives the references from Bhagwat Purun rather than Vedas and Vedic scripture. Even Dr. Creamo takes the references from Bhagwatam instead of the Vedic scriptures of Vedang Jyotish which is supposed to be the major treatise for understanding the ancient system. Even at some instances, where the Vaishnavs talk about Vedas, their interpretation is based on Pauranik tales rather than the Vedangas like Nirukta, which are the sources of Vedic interpretation. You will find hardly any text from Vaishnavs, where they will refer for Nirukta for the Vedic interpretation.