The run time of the three tests are almost the same.

gistfile1.js

var should = require('should');
var Benchmark = require('benchmark');

var suite = new Benchmark.Suite();

var lambdaLifting = function () {
  var x = 10;
  function fn() {
    return x + 1;
  }
  return fn();
};

var change = function () {
  var x = 10;
  function fn() {
    x += 1;
    return x;
  }
  return fn();
};

var fn = function (x) {
  return x + 1;
};

var normal = function () {
  var x = 10;
  return fn(x);
};

suite
  .add('lambda lifting', function () {
    var num = lambdaLifting();
    num.should.equal(11);
  })
  .add('change state', function () {
    var num = change();
    num.should.equal(11);
  })
  .add('normal', function () {
    var num = normal();
    num.should.equal(11);
  })
  .on('cycle', function(event) {
    console.log(String(event.target));
  })
  .on('complete', function() {
    console.log('Fastest is ' + this.filter('fastest').pluck('name'));
  })
  // run async
  .run({ 'async': true });