Been living CouchDB and BigCouch all week, specifically migrating our cluster of 6 Couchbase Server 1.0.2 single instance VMs to a single BigCouch cluster.
Process was damn smooth--basically just shut down three nodes (due to BigCouch's quorum system you want a minimum of three nodes in a cluster) and nuked Couchbase and all the data, installed BigCouch, clustered those three nodes, and then did one-off replication for each of the database from one of the still-live Couchbase servers to one of the members of the new BigCouch cluster.
Once the replication finished and I verified the document counts I shut down the remaining three Couchbase servers, nuked Couchbase on those, installed BigCouch, and added them to the BigCouch cluster.
Pretty amazing I could completely change my underlying infrastructure like this with no down time and do the whole thing in an evening with the bulk of the time spent just babysitting to make sure replication didn't show any write fails. Installing BigCouch was literally three commands in a terminal.
This is pretty basic stuff but I'll probably blog it all for posterity while it's fresh in my mind. I also wrote up what I think is a pretty definitive guide to Couch security which is still something that throws a lot of people, so I'll share that as well.
Still unbelievably happy with Couch overall and having a single BigCouch cluster instead of having to manage 6 single instances clustered behind a load balancer with continuous replication going (cool as that stuff is) is going to make life a lot easier.