Make sure tracing and debug is turned off
Find the following lines in your web.config file and make sure the attributes are set to false, it makes a noticeable difference:

< trace enabled="false" requestLimit="10" pageOutput="false" traceMode="SortByTime" localOnly="true"
...
< compilation defaultLanguage="c#" debug="false">
...
< add key="umbracoDebugMode" value="false">

Umbraco.