Does unlimited usage in early plans destroy your power-user upgrades?

To make our mid-tier plan appealing we included generous usage limits thinking people would upgrade once they felt the value.

Instead power users optimized their workflow just to stay right under the threshold. Once we switched to feature gated tiers instead of usage-based limits users upgraded much faster because they actually hit functional walls instead of artificial caps.

Do you find feature-gating or usage limits work better to drive tier upgrades?