Is a 1.75 GPM WaterSense rainfall head worth it?

For most households, yes. WaterSense-certified 1.75 GPM heads from major brands are engineered around the lower flow rate, and reviewers we read who installed them generally don't describe the drop from 2.5 GPM as a hardship. They also qualify for utility rebates in some regions. Cheap unbranded heads at 2.5+ GPM can feel stronger but waste water and may have flow restrictors that owners pop out anyway.