Just want to harp on your first point - MongoDB's storage problem is uniquely Mongo's and not indicative of NoSQL design. Compactions can be a pain and the lack

Just want to harp on your first point - MongoDB's storage problem is uniquely Mongo's and not indicative of NoSQL design. Compactions can be a pain and the lack of compression + the some design features (such as no symbolized keys) can lead to a very bloated database. We ran a MongoDB cluster with 5 nodes on 1TB SSDs that were 80% full and growing (and we had no replica sets, a nightmare). We switch to Cassandra, and even set the replica factor to 3 and we only managed less than 30% disk usage. Now when I think about MongoDB administration, I'm now also thinking cost. Pound-for-pound (same number of replicas and nodes, and not even counting wanting to keep your nodes under 50%) our MongoDB cluster cost would 5x more while delivering worse performance. It really isn't an issue of MongoDB using a large amount of space, its an issue of MongoDB using an order of magnitude more of space leading to uneccesary higher production costs.