It's not content that you can play or see or feel - you don't even notice that it's there. Wow is utilizing for usage of multicore cpus.
Whenever you judge 8.1 and "how less content" it might be and how bad the timegating is and such keep in mind that this change is a major tech step. We can be glad that a raid is added because from the technical point of view that's really not an easy update. In fact that could break several things but opens up alot of opportunities.
Further explaination:
https://www.youtube.com/watch?v=-nAUuBcEwUs
Would be nice to spread the word... that's something that is needed once in a while to maintain software but it's always forgotten when judging features.