let msg = [{ _id: 5cef45879e78602774e921d0,
    to: '5ce82f0deee6dc458a20b21e',
    from: '5ce82f0deee6dc458a20b21e',
    text: '5',
    type: 'text',
    user:
     { id: '5ce82f0deee6dc458a20b21e',
       name: 'usuario4.2',
       display: 'usuario4',
       descript: 'usuario4',
       avatar: 'blazer2.png',
       createdAt: 1559184735135 },
    channel: '/geral',
    createdAt: 1559184775656 },
  { _id: 5cef45789e78602774e921cf,
    to: '5ce82f0deee6dc458a20b21e',
    from: '5ce82f0deee6dc458a20b21e',
    text: '4',
    type: 'text',
    user:
     { id: '5ce82f0deee6dc458a20b21e',
       name: 'usuario4.2',
       display: 'usuario4',
       descript: 'usuario4',
       avatar: 'blazer2.png',
       createdAt: 1559184735135 },
    channel: '/geral',
    createdAt: 1559184760319 },
  { _id: 5cef406c52c9ec1e37065be7,
    to: '5ce82f0deee6dc458a20b21e',
    from: '5ce82f0deee6dc458a20b21e',
    text: '3',
    type: 'text',
    user:
     { id: '5ce82f0deee6dc458a20b21e',
       name: 'usuario4.1',
       display: 'usuario4',
       descript: 'usuario4',
       avatar: 'blazer2.png',
       createdAt: 1559183392625 },
    channel: '/geral',
    createdAt: 1559183468769 },
  { _id: 5cef406952c9ec1e37065be6,
    to: '5ce82f0deee6dc458a20b21e',
    from: '5ce82f0deee6dc458a20b21e',
    text: '2',
    type: 'text',
    user:
     { id: '5ce82f0deee6dc458a20b21e',
       name: 'usuario4.1',
       display: 'usuario4',
       descript: 'usuario4',
       avatar: 'blazer2.png',
       createdAt: 1559183392625 },
  { _id: 5cef406352c9ec1e37065be5,
    to: '5ce82f0deee6dc458a20b21e',
    from: '5ce82f0deee6dc458a20b21e',
    text: '1',
    type: 'text',
    user:
     { id: '5ce82f0deee6dc458a20b21e',
       name: 'usuario4.1',
       display: 'usuario4',
       descript: 'usuario4',
       avatar: 'blazer2.png',
       createdAt: 1559183392625 },
    channel: '/geral',
    createdAt: 1559183459121 } ]

Então rodei let x = msg.map(res => res.user) dai consegui..




{ id: '5ce82f0deee6dc458a20b21e',
   name: 'usuario4.2',
   display: 'usuario4',
   descript: 'usuario4',
   avatar: 'blazer2.png',
   createdAt: 1559184735135 },
 { id: '5ce82f0deee6dc458a20b21e',
   name: 'usuario4.2',
   display: 'usuario4',
   descript: 'usuario4',
   avatar: 'blazer2.png',
   createdAt: 1559184735135 },
 { id: '5ce82f0deee6dc458a20b21e',
   name: 'usuario4.1',
   display: 'usuario4',
   descript: 'usuario4',
   avatar: 'blazer2.png',
   createdAt: 1559183392625 },
 { id: '5ce82f0deee6dc458a20b21e',
   name: 'usuario4.1',
   display: 'usuario4',
   descript: 'usuario4',
   avatar: 'blazer2.png',
   createdAt: 1559183392625 },
 { id: '5ce82f0deee6dc458a20b21e',
   name: 'usuario4.1',
   display: 'usuario4',
   descript: 'usuario4',
   avatar: 'blazer2.png',
   createdAt: 1559183392625 },

let unic = x.filter(function (a) {
                    return !this[JSON.stringify(a)] &&
                    (this[JSON.stringify(a)] = true);
                }, Object.create(null))

[ { id: '5ce82f0deee6dc458a20b21e',
    name: 'usuario4.1',
    display: 'usuario4',
    descript: 'usuario4',
    avatar: 'blazer2.png',
    createdAt: 1559183392625 },
  { id: '5ce82f0deee6dc458a20b21e',
    name: 'usuario4.2',
    display: 'usuario4',
    descript: 'usuario4',
    avatar: 'blazer2.png',
    createdAt: 1559184735135 } ]