To optimize performance and improve operations in Amazon Web Services (AWS), integrating New Relic's AWS Metric Streams with AWS CloudWatch is essential for comprehensive visibility, real-time alerts, enhanced visualization, scalability, and flexibility. By sending AWS CloudWatch metrics to New Relic, users can gain a unified view of their AWS environment alongside other application performance metrics, simplify monitoring, and troubleshoot faster. The choice between using AWS API polling or CloudWatch Metric Streams depends on specific requirements, complexity tolerance, and cost considerations, with CloudWatch Metric Streams being less expensive and providing real-time data, low overhead, and customizability. New Relic offers a widget to compare costs, and best practices for integration include defining monitoring objectives, creating custom dashboards, configuring alerts, and regularly reviewing and optimizing performance data.