I tried out gundb in node.js. Calling once after calling get two times results in an error. I did the following in the node console:
var Gun = require("gun/gun");
var gundb = Gun();
gundb.get('user').get('friends').put({name:"Joe"});
gundb.get('user').get('friends').once(function(data,key){ console.log(data);});
and I got the following error:
{ err: 'Error: No ACK received yet.', lack: true }