The heroic version of the Ragnaros fight adds a whole new phase to the encounter in which Ragnaros regains his full Firelord strength, steps out of his swirling molten pool, and becomes mobile around the platform with his new firelegs. Cenarius, Hamuul Runetotem and Malfurion Stormrage assist the players in tackling Ragnaros' many abilities in this new phase, finally putting out the Firelord's lights for good.
Heroic modes for the Ragnaros fight and others in the Firelands were also not available on the public test realm, making it that much more difficult for these hardcore raiding guilds to get time in on these encounters.
I am excited to hear about Paragon's time with these bosses in the Firelands. At only seven bosses, the Firelands is one of the more accessible raid zones, with a time commitment that feels far smaller than the monolithic endeavors of the past, like ICC or Ulduar. Has Firelands presented enough of a challenge to the top of the top guilds? Whatever the case, congratulations again! I hope that my guild will be at heroic Rag's door in the near future.