I didn't know about the stale attribute for couchdb(mentioned in a comment in the article). I can see places where it will speed up things in our set up.

Also, Mongo DB is interesting and I have plans to evaluate it for our setup(batch reads and writes, no master-master replication requirement, but need master-slave replication, also need sharding rather desperately). Does anyone have any experience couchdb-lounge mentioned in the same comment?