In terms of content I think WoD had some good stuff. The dungeons imo were mostly good, the raids were actually pretty great. But the lack of content outside of that, combined with Tanaan just not being very fun imo, and all the scrapped ideas. That expansion only had 3 raids. I think they could have done more fun things with the story as well but it was disappointing how they scrapped the planned Netherstorm stuff and the Shattrah raid and so on. Also I remember how cool it was when it was planned for the garrison to potentially be built in any of the new zones but ultimately it was a fixed position and it just felt a bit lame.