Never get tired of seeing Heavensward brought up in this context. Early HW AST was nearly unplayable. Diadem flopped, got redone, and flopped again. Feast 2.0 did nothing to revive PVP. HW raiding almost killed the raid scene outright. All of it added up to make 3.4-3.5 kinda sleepy community-wise.

I would really, really think twice before holding HW up as a paragon - it's very easy to turn it into a golden age fallacy.