Какой из кодов эффективнее?

function reverseString1(str) {
    return str.split('').reverse().join('');
}
function reverseString2(str) {
    if (str.length == 1) return str;
    return str[str.length - 1] + (reverseString2(str.slice(0,str.length - 1)));
}
function reverseString3(str) {
    let result = "";
    for (let i = str.length; i--;) result += str[i];
    return result;
}

// An input string of 200 characters:
let str = "asirjsmpfuenndlsuegi".repeat(20);
console.info("Tests...");
const suite = new Benchmark.Suite("reverse string");
suite.add("split&join", () => reverseString1(str))
     .add(" recursive", () => reverseString2(str))
     .add("  for-loop", () => reverseString3(str))
     .on('cycle', (event) => console.info(String(event.target)))
     .on('complete', () => 
         console.info('Fastest is: ' + suite.filter('fastest').map('name')))
     .run({ 'async': true });

<script src = "https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.4/lodash.min.js"></script>
<script src = "https://cdnjs.cloudflare.com/ajax/libs/benchmark/2.1.4/benchmark.js"></script>