Here comes AIzen's true source of power...THE MULLET!
Well, this was somewhat enjoyable, as a bonus to seeing Gin's face clearly (5:23) and finally using his zanpakuto in the most awesome way of a repeated piercing salvo, he gave a nice speech too! The top three captains fell rather easily, what with no bankais and stuff, but Urahara gave a good performance.
Important note: Through Aizen, Kubo admits that there is no logic behind bleach power levels, because he destroyed the Koutotsu and thus defied logic.