Neo4j handles read/write seamlessly I have found, but I'm only around 10,000 nodes and 20,000+ edges. I've heard use cases for Neo4j in the range of 50M+ nodes.

Neo4j handles read/write seamlessly I have found, but I'm only around 10,000 nodes and 20,000+ edges. I've heard use cases for Neo4j in the range of 50M+ nodes. My position on this is not whether Neo4j can handle it but whether your code and infrastructure can.