The thing is I've been debating which two parter in my head is better, Discord or the Wedding, and I'm sorry John de Lancie, I love ya but I think the wedding was better, the villain reveal was much more of a surprise, there were songs, the pacing felt so much better, both endings seemed rush but the wedding one felt a bit less rushed, I always felt the pacing of the Discord episode, at least the first part was way to fast, we were basically spoon fed exposition and I hate having that cause of Anime syndrome.

Discord plus and cons
+John De Lancie
+Opposite elemental ponies
+Screwball and all the other whacky stuff (chocolate rain and exploding chocolate milk)
-Spoon fed exposition
-No songs
-Ending felt way to rushed
-Fluttershy's corruption felt cheap and rushed making you wonder why he went through the trouble of setting up scenario's in the first place if it just takes a poke
-Celestia and Luna are no where to be seen helping the mane 6 with the villain and much rather be enjoying their golf game.
Wedding episode
+New surprise villain with an awesome design
+New race
+3 great songs
+Every pony had a major part to play
+Celestia actually (well at least tried) helped for once
+The pacing was perfect (with a very small exception for the end)
- Princess Cadence was a bit too much of a marie-sue
-The ending again felt a bit rushed but not as rushed as Discords
-Rarity didn't have a segment with the changelings (I would of loved to have seen a scene with her criticizing the changelings of minor in-corrections on their forms, like a flank being a bit too big)
-The end of part 1 when Twilight is implied to be offed or at least incapacitated and then it went into the really jarring happy credit music when it should of stayed silent for suspence
-TORI SPELLING TORI SPELLING TORI SPELLING TORI SPELLING TORI SPELLING TORI SPELLING TORI SPELLING TORI SPELLING

That's my 2 cents anyway.