Western Union Quick Cash payments will be available for pick-up the day after the payment date. The countries where Quick Cash is possible are :

China (Mainland)
Malaysia
Pakistan
Romania
Philippines
Argentina
Chile
Peru
Colombia

The comissions for the Quick Cash service are NOT the same as for the normal Western Union money transfer (hundreds of USD).

In Romania, at least, the commisions are this way (these comissions are NOT present or stated anywhere within the Google Website, nor the Western Union website):

$15 for any sum up to $3000 USD
$25 for any sum exceeding $3000 USD

The maximum payment through this service is $5000. If your payment exceeds $5000, the payment method will automatically convert to the standard check.

You can search valid Western Union agents in your city, that allow QuickCash payments, through Payment Solutions.

When will you receive a payment ? Next day :)

Read more about it in SeoPedia forum (romanian).