Using a controller felt incredibly liberating, taking WoW from a more intense engagement in keys to a tad more casual and relaxed experience. Things like World Quests became a more kick back experience, which felt amazing to my back! It really helped take some of the keyboard stress off of my hands, such as my thumb which had been having a lot of pain from constantly being on space bar without moving much.
In dungeons, I found swapping quickly to interrupt things to be sort of difficult. Pushing tab vs up on the D Pad isn't nearly as flexible, although there may be better setups for targeting that I haven't found yet, such as using R1 for that instead of my right mouse button. The Fury Warrior rotation fits so perfectly with controller, it feels like an ARPG rather than an MMO. Movement felt a tad difficult when I had to run out of bad, which led to relying on Heroic Leap a bit more often though, since there is some minor "keyboard" (controller) turning involved, which isn't as quick as when using a mouse.
I also found it super easy to stay on boss and move and DPS. When using WASD, I always felt a tad limited when trying to do my rotation while staying on boss and moving around it, and that was a total total nonissue with the controller. Bosses in general felt so much more fun and honestly easier in a lot of ways as well. I will say that PvP felt really bad against constantly moving ranged characters though, but it felt great when fighting against other melee.