Swapping talents that changed the game play for fights was fun - definitely not against that. Having to flip nearly every talent from fight to fight, was not. It was the same builds for each specific fight. That wasn't interesting. The ease of changing made it mandatory. Always had a stack or two ready to do so. On top of swapping legendaries/gear, which was fortunately automated so you could just click a button. Also needed to switch around a couple primary abilities on the cast bar. If you could have saved builds, would have been a lot less of a nuisance.
During WOD you could generally run a single build for an entire raid. Maybe change them for PVP or a slight change for dungeons vs raids or whatever. Vanilla/TBC was a whole other monster with sacrifices made to raid and pvp. Wrath was pretty set it and forget it, don't recall doing much changing. Cata introduced the trimmed down, modern talent system, but didn't really offer variability.
If you're going to make it "easy", go all in.
