I do not consider Hare Krishna a modern religion. It is sect of an ancient religion. By far the beliefs are pretty standard ancient Vedic views common to the various forms of Hinduism.
It may be called a sect one one hand, yes. It represents a revival of Vedic orthodoxy. To put in brief KRISHNA is the purpose behind the Vedic enlightenment/Salvation/Liberation ---versus the notion of nirvana. Nirvana is anathema to the Vedic conclusion of spiritual knowledge.