I have power steering and it does not seem to be necessary, but have not yet compared it to one without the option.
On US models the Power Steering option is available two ways:
$450 for just Power Steering.
$850 for the Comfort Package (Power steering, Leather seats, Rain sensing wipers, Light sensor, Auto-off headlamps with exit delay)
The comfort package seems like a bargain unless you don't want leather.