The good news:
I think the scenes showing the Last Battle itself (the part fought by Mat and Co. at least, as well as the previous battles around Andor, the Borderlands, etc.) were very well done and suitably epic for the story. There were a couple of nice twists that I thought were quite brilliant--the fall of the great commanders, sophisticated uses of gateways, the appearance of the heavily-foreshadowed Demandred and the Sharan army, the intentional use of balefire to mess up the world, etc. I do wish that there had been more than just Trollocs and the occasional distant Dreadlord in the Dark One's armies though: Trollocs haven't been a real threat since the third book, so it's hard to treat them as such anymore. The relationship with Androl and Pevara, and the liberation of the Black Tower were all very entertaining. The chaos and small triumphs of various characters in the war were nicely played out. The story wrapped up most of the dangling threads in a sensible, if not always wholly satisfying, way.
The bad news:
I feel that the story basically abandoned any semblance of characterization in pursuit of plot. There were a lot of character reunions that had the opportunity to be really significant and heartfelt, but the story often rushed through those moments without really taking the time to appreciate their significance. Rand and Mat haven't seen each other since book 5 (I think) and get about a page together before rushing off. Likewise for Rand and Perrin. For all the fanfare of rescuing Moiraine, she was remarkably underused in the plot on any level. Despite splitting the book in three, I think that there was still probably too much material in this book for it to work really well--as I said, I thought the Last Battle in Mellinor was good, but the battle in the Blight received little attention, and the battle between Rand and the Dark One even less.
I was very disappointed by the death of Padan Fain. For being one of the most prolific villains of the entire series and for having such great strength and interesting abilities, he only showed up a few pages before the end of the book and left just as quickly in a rather anti-climactic way. Likewise, I would have liked to have seen Moridin have a more interesting role, and, for that matter, Shadar Haran, who was entirely absent. Demandred got the starring villain role; unfortunately, isn't nearly as interesting as the other two, if, for no other reason, than that he hasn't really been in the story at all prior to this point in any significant way. Having him fight three consecutive duels against characters he had never met in the series was not particularly inspired, or, at least in the cases of Galad and Lan who wouldn't be able to easily slip through the Sharan lines, particularly realistic. I think there were lots of ways that this book could have been written that would have been much better than what was produced.
Almost forgot... No mention of the "great treasure trove" of knowledge and wisdom that Verin had offered to Egwene? That was one of the better scenes, and twists, in the whole series and it went nowhere.