Angmar was always my favourite faction, and even more now! Designs are amazing, Helegwen is a great new hero... I also love that now Karsh can always be on field (If I remember correctly, in 3.8.1 he had a timer). I love all hero concepts, and the way of leveling up buildings.
My favourite thing about this faction is their variety. Orcs, Hillmen, Men of Cârn Dum, Wolves... It seems like an alliance of all the Evil in the North of Middle-Earth, and I love that. I also love how almost every part of the faction has a Hero that represents them (Mornamarth for Carn Dûm, Dûrmarth for the Black Guard...) Rogash's adittion to the Spellbook is also great.
The only thing I don't like is the Witch King Ring Hero bonus. I mean, bonuses are great, but it feels like he needs something more to be at the same level of the rest of Ring Heroes.