Can you explain further? I tend to agree because the claim that "graph databases are good for highly connected data" seems funny - can't relational databases be "highly connected" in the same way? Isn't it really about query languages or maybe writing expressive schemas? I don't see how claims about efficiency stand up to an objective critique.

The issue at hand was to define vertexes with relationships and look up and track those. More writes than reads. I wasn't lead on it after the initial review and testing, but if you're doing something super simple, do it on postgress, I'd say. If you're doing something medium complex, use an off the shelf graphDB but beware rough edges and newness bugs. If you're doing something large scale and unique, talk to smarter people than me - I can introduce you :-)