The third note in the progression sounds a bit odd up until 35 seconds in, then it sounds fine after that. Also, the thing from 1:37 to 2:29 stretches on a liiittle too long, but I think the "boring" sample is an epic transition to the part after it All in all, nice job! I like it.
I like this quite a bit as its a real good use of the vocal samples and I love the co-incidence of the Pinkie breakdown with the breakdown of the song (zing!). Good job.