It all depends on what client you are using. For example PHP 4.3.x if you are using this, it does not work with prepared statements. But PHP 5.0 does work with prepared statements if you use the mysqli commands.
Since 4.1.x is fairly new some clients still do not support the prepared statements which technically is faster.
We use PHP, and since we are not using PHP 5 yet, we can't use prepared statements. But the table cache and the query cache at least in our opinion are just as fast as prepared statements will be in the future.
Donny