Synchronous replication ensures strong consistency by replicating data immediately across multiple servers, but it comes with high latency and processing overhead due to the need for coordination between clusters. Asynchronous replication offers lower latencies and higher throughput by replicating data in the background, but it may introduce eventual consistency and require conflict resolution mechanisms. The choice between synchronous and asynchronous replication depends on the application's requirements, prioritizing availability, consistency, or performance. Advanced approaches like Aerospike's XDR system aim to minimize overhead while maintaining high availability, scalability, and low latency.