My opinion is pretty much the same as anyone else that has an I.Q. of above room temperature. The first two episodes of the season were tacky, and rather slung together.
King Sombra was an extremely boring villain with pretty much no redeeming qualities. Instead of making the character interesting and fun they decided to simply give him a cool look and glow. They didn't bother to explain much more about him than "ooh, he's evil and scary", which honestly irritated me a lot. His only goal was tedious and repetitive because 'I want to take over and enslave everyone' has been done a million times. To top it off, his defeat was also as tacky as Chrysalis's. He was defeated by an explosion and disintegrated. Wonderful.
The songs were okay in my book. They certainly aren't anything to be overly proud of, and I wouldn't really call them necessary. They seemed to be thrown in for the sake of having a song rather than having something that would be worth it in the overall look at things. When it comes to these, I think that season two did better song wise.
I think there were at least some redeeming funny bits here and there. The one that caught my eye the most was Pinkie having disguised herself as Fluttershy. That was random, and extremely funny. Definitely a fitting piece of humor for Pinkie Pie overall. I don't really have anything bad to say about the bits that were supposed to be funny, because they were just that; funny.
It seemed pretty much the same as the season two finale, but with different setting and characters. Someone was holding up a protective field and it was wearing on them, causing them to falter and allow the enemy inside. I can't say that this was at all the best piece of writing. Like I said, it all seemed rushed. What I think is that the writers were in a hurry to kick off season three and just took a copy of the ending of season two and called it a new episode just to appease the viewers, which really irritates me.
Overall Score: 2.5/10