Which is better?

expire1.js

exports.handler = (event, context, callback) => {
  var ec2 = new AWS.EC2({region: process.env.AWS_REGION});

  ec2.describeSnapshots(params).promise()
    .then(data => {
      return Promise.all(
        data.Snapshots
          .filter(snap => daysOld(snap.StartTime) > MAX_AGE)
          .map(snap => ec2.deleteSnapshot({SnapshotId: snap.SnapshotId}).promise())
      );
    })
    .then(results => {
      callback(null, `Deleted ${results.length} snapshot(s)`);
    })
    .catch(err => {
      console.log(err, err.stack);
      callback(err);
    });
};

expire2.js

exports.handler = (event, context, callback) => {
  var ec2 = new AWS.EC2({region: process.env.AWS_REGION});

  ec2.describeSnapshots(params).promise()
    .then(data => Promise.all(data.Snapshots
                              .filter(snap => daysOld(snap.StartTime) > MAX_AGE)
                              .map(snap => ec2.deleteSnapshot({SnapshotId: snap.SnapshotId}).promise())))
    .then(results => {
      callback(null, `Deleted ${results.length} snapshot(s)`);
    })
    .catch(err => {
      console.log(err, err.stack);
      callback(err);
    });
};