The latter is represented by none other than Werner Vogels, the CTO of Amazon, godfather of Dynamo (from which all current key-value stores are inspired) and probably the top expert in the world at building large-scale distributed systems.
The best part is at the end (around minute 45), when the participants were asked to name their favorite nosql systems, except their own. Werner Vogels concluded with saying:
"For anything with multiple relationships, multiple connections, Neo4j absolutely ROCKS!"
A statement we wholeheartedly agree with. :) Listen to the entire clip here.