Que opinan de esta clase que hice

[negro1985]

Código:

<?php
class Conexion
{
    private $cn;
    private $rs;

    public function __construct($serverName = "localhost", $user = "root", $pass =
        "220785", $db = "sce")
    {
        $this->cn = new mysqli($serverName, $user, $pass, $db);
    }

    public function dbExecute($query)
    {
        $this->rs = $this->cn->query($query);               
        return $this->rs;
        $this->cerrar();
    }

    public function getInsertedId()
    {
        return $this->cn->insert_id;
    }

    public function getAffectedRows()
    {
        return $this->cn->affected_rows;
    }
    private function cerrar(){
        return close($this->cn);
    }
}
?>

Que le mejorarian a esta clase que hice para conectarme a mysql