Admittedly I haven't used older versions of Cassandra, or under as much load as I have Postgres or Mongo. My point was that it is designed for being distribute

Admittedly I haven't used older versions of Cassandra, or under as much load as I have Postgres or Mongo. My point was that it is designed for being distributed and it doesn't hide that fact. Mongo's replica sets and sharding are much less transparent and much less predictable.