Talvez hago mal el Test... pero me salta que es mas rápido crear 1000 elementos con DOM que innerHTML....
pueden probarlo?
Código PHP:
   <html>
        <head>
                <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
                <title>asdasdasdasd</title>
        <script type="text/javascript">
        var samp_bench=function()
{
    var g=document.getElementById("bla");
    var t=document.getElementById("target");
    t.innerHTML="";
    var startTime=new Date().getTime();
    for(i=0;i<1000;i++)
    {
        var a = document.createElement("span");
        t.appendChild(a);
        var endTime=new Date().getTime();
    }
    g.innerHTML = "Con DOM =>"+(endTime-startTime);
}
var samp_bench2=function()
{
    var g=document.getElementById("bla");
    var t=document.getElementById("target");
    var startTime=new Date().getTime();
    t.innerHTML="";
    for(i=0;i<1000;i++)
    {
        t.innerHTML+="<span></span>"
        var endTime=new Date().getTime();
    }
    g.innerHTML = "con InnerHTML=>"+(endTime-startTime);
}
        </script>
        <style type=text/css>
            .pan{
                background-color:#FFFFFF;
                border:1px dashed red;
                width:200px;
                height:50px;
                color:white;
                font:normal 0.8em Tahoma,MiscFixed;
                text-align:center;
                vertical-align:bottom;
            }
        </style>
        <link rel="stylesheet" type="text/css" href="style.panel.css" />
        </head>
 
    <body>
        <input type="button" value="1000 elementos con document.createElement!!!!" onclick="samp_bench();">
        <input type="button" value="1000 elementos con innerHTML !!!" onclick="samp_bench2();">
        <div id="bla"></div>
        <div id="target"></div>
        </body>
</html> 
   connection closed.
 
 



