of all this debate....when in reality in the spiritual realm there is no difference between the source and the avatar? (as documented in the Vedas). one may worship any form of the Supreme Lord and achieve the abode of that Lord. So, if you are a worshipper of Lord Narayan, all glories to you! Whether its Vishnu or Krishna, both are in the category of Vishnu-tattva.
now....as to why we cherish our beloved Shyamsundar soooooo much. While the aishwarya and magnificence and wonderfulness of Vishnu is beyond our calculation, it is also an undeniable fact that the sweetness and lusciousness of Shri Krishna's qualities and leelas are unmatched, in any other God or avatar, in any Sanatan Dharma sampradaya or any other religion. This, i firmly believe, is NOT a Gaudiya concoction.
Haribol!