Season 2 started off great and very promisingly, very much like how Season 1 started off. The season did vary post-"Luna Eclipsed", thankfully more hits (the best being "Sisterhooves Social", "A Canterlot Wedding Part 2" and "Hurricane Fluttershy") though than near-misses (four episodes particularly are disappointing, "The Mysterious Mare Do Well", "Hearts and Hooves Day", "Putting Your Hoof Down" and "Dragon Quest", but still don't consider any of them unwatchable, more average at best).
The season ended on a very good/great, if not quite flawless, note with the two part finale "A Canterlot Wedding". While preferring the darker, more emotionally varied and meatier second part, Part 1 is still very good indeed with a lot of fantastic things. As well as a couple of not too major annoyances that are thankfully outweighed by what works so well. Both parts are among the best episodes of the second season and a fine way to end it.
Will start with the not so good things first. Personally didn't really buy how quickly and easily Twilight was turned upon. The episode ends on a cliffhanger, which did attention grab but was also too abrupt.
Cadance's true intentions were obvious far too early and in so obvious a way that it makes Twilight's turn upon even more unconvincing.
However, the animation is great with both parts of "A Canterlot Wedding" being among the season's and show's best looking episodes. Part 2 is even better looking, but the atmosphere and attention to detail looks great here in Part 1. The music is full of atmosphere and character, the song "BBBFF" saying a lot about the characters singing them. The writing is some of the season's best, amusing, tense and affecting. Especially with Cadance and Twilight.
Moreover, Twilight's character writing is just fascinating and her arc has a big emotional core that is genuinely poignant. Cadance is a great character and Celestia's character writing is her most interesting in a long time. Authoritative and vulnerable, while proving herself useful. It was great to see everybody seeming genuinely concerned. The voice acting is terrific, especially from Tara Strong.
In a nutshell, very good but the second part is better. 8/10