I love what Casandra does and I think it's the best of the NoSQL options out there.
I'd say that the differences between types of NoSQL databases preclude any attempt to choose a winner. It's makes no more sense than trying to pick the better between NoSQL and RDBMS.
I think this illustrates much of the problem with the NoSQL moniker - it seems like an attempt to group a bunch of completely different data storage systems by arbitrarily excluding a single one.
I'd say that the differences between types of NoSQL databases preclude any attempt to choose a winner. It's makes no more sense than trying to pick the better between NoSQL and RDBMS.
I think this illustrates much of the problem with the NoSQL moniker - it seems like an attempt to group a bunch of completely different data storage systems by arbitrarily excluding a single one.