How much should I trust stat weights?

Stat weights are a starting point, not a law. Your gear, talents, trinkets, tier, and content type can change what feels good or sims best.

Exactly. Use stat priority to avoid obviously bad gearing, then compare actual pieces with sims, logs, or live leaderboard examples.

For healers especially, stats also depend on damage patterns. A raid ramp build and an arena build can value very different things.