(I was rummaging around in Gaudiya Discussions and came across this, which I though was worth preserving here. I was surprised a little to see myself using vocabulary and themes that I am still hammering away at. Some of the points might require a little bit of revision.)
Raganuga bhakti means imagining yourself as a part of Radha and Krishna's world, and doing all sadhana in that consciousness. Vidhi bhakti is primarily conducted only in the sadhaka deha--hearing, chanting, etc., are all there, but the goal of being with God (in whatever form) is left in his hands. "Give me whatever service YOU want."
Raganuga bhakti begins with the prayer, "I want specifically THIS in Radha Krishna's world." The raganuga bhakta's sadhana is mystical participation in the divine realm.
Through raganuga bhakti, one quickly ceases all prayers for liberation because one practically loses all consciousness of being a sadhaka. This colors his perception of and participation in this world.
Think about it. Yashoda's love is higher than Raktaka or Patraka's. Yashoda goes to get the boiling milk, but Krishna wants her to stay and breastfeed him. So she is making Krishna angry, but she is still only thinking of pleasing him.
This is explained in the commentary to the anyAbhilASita-zUnyam verse. AnukUlyena kRSNAnuzIlanam. Ultimately, Krishna puts himself under the control of Yogamaya, and the devotees are also under Yogamaya. They are engaged in the various pushings and pullings of divine prema, nothing else. So Yashoda knows better than Krishna what he wants or needs. Radha knows better than Krishna what he wants or needs. Even the manjaris are stopping Krishna at the door to Radha's kunj and saying, "Sorry, Kanai, we cannot let you in. It will give our Swamini too much pain if she sees you after all the nonsense you have been doing. Go and find some nice chocolates and some red roses or something, because if you come empty-handed like this, she'll bite your head off. Come back tomorrow and we'll let you know if you have a chance to get in and see her."
And sometimes Krishna even touches the manjari's feet and says, "Please, please intervene on my behalf," and the manjari still has to say no because she knows how real Radha's pain is.
So is this activity pleasing to Krishna? Krishna is so overwhelmed by Yogamaya that he cannot think straight. He cannot manifest a four-armed Narayan form and order the manjari, "You little dasi girl! Who do you think you are? You're a jiva and I am ishwara. How arrogant you are to think you can stop me from going into Radha's kunja if I want to!"
That is the price Krishna himself has to pay to taste the love of his devotees. He has to renounce his God-ship and give it to Yogamaya. He has to relegate power to her to create and maintain the world of his lila.
Raganuga bhakti means cultivating the mentality that makes you eligible to enter this world--the world that Krishna himself says is the dearest to him. Bhakti always comes out of bhakti, but vidhi bhakti says "Bhakti means service, and service will lead to love" (like an arranged marriage). Raganuga bhakti says, "Bhakti is the attraction I feel to Krishna. If this bhakti develops, it leads to prema."
It is almost backwards. It doesn't even seem like service. It is saying, "I will cultivate this attraction. I will cultivate the joy and emotion of absorption in Krishna's name, form, qualities, pastimes and associates, and service will automatically come from that like a secondary result."
In fact, how can relishing Krishna's name, form, qualities and pastimes even be considered service? It is sheer delight, so shouldn't it be called ego-centered sense gratification? No, it should not, because the highest service is to become a part of his world, where everything is Krishna-maya. There, everything is natural absorption in him, everything is done for him, and everything has within it the automatic reward of absorption in him, sac-cid-ananda vigraha.
The vaidhi bhakta tries to break away from this material world. The raganuga bhakta transforms this material world with his vision. Everything is stamped with Krishna consciousness.
The reason raganuga bhaktas say that the vaidhi-bhakta can follow his sadhana for a million years without attaining raganuga bhakti (sAdhanaughair anAsaGgair alabhyA sucirAd api) is that vaidhi bhakti has a certain mentality of reservation attached to it. That mentality is cultivated by the vaidhi bhakti process. A culture means that it only becomes stronger.
So it is quite possible to pay lip service to the Vraja bhava without ever really entering into it. There is a kind of letting go, or surrender, a leap of raga, that transports a bhakta from the vaidhi mentality to the raga one.
Some people (usually those on the vaidhi side of things) argue that the current system of initiations, siddha pranali, etc., are a kind of vaidhi bhakti because they require following rules, etc. This is actually a misunderstanding of the difference between raga and vaidhi bhakti. The difference in the two is not so much what is done externally, but the internal attitude with which they are done. Through the siddha-pranali system, the aspiring devotee actually becomes invested with a natural sense of connnectedness and belonging to that realm. Externally, that connectedness comes through the disciplic chain leading to a direct associate of Chaitanya Mahaprabhu and internally through the association of siddha manjaris and sakhis who participate directly in that lila. That is the real magic of initiation in the Gaudiya sampradaya.
Another objection sometimes heard from the "antiparty" ;) is that the Gaudiya Vaishnavas do not appreciate viraha or separation because they cultivate the sense of appurtenance. This is ludicrous nonsense. Separation can only be felt because one feels one belongs so intensely that even the illusory sense of separation burns like a thousand flames. But just like people in this world report that once a certain pain threshold has been crossed one loses consciousness, so too does the pain of separation transport one into a sense of identity with Goloka. Like Mahaprabhu floating in the ocean off Puri.
No one cultivates separation; one cultivates union. Separation is Yogamaya's imposition on union, the flame whereby the gold of prema is smelted and purified to ever greater brilliance.
There are many misconceptions about raganuga bhakti, which is generally called Sahajiyaism by those whose understanding is superficial.