A major advantage of using a WICED module is that if the PCB design and the external components are unchanged then the radio does not require recalibration in production as this has been addressed during the design of the module. This is a different approach to some other solutions which do require a calibration step in production and therefore a larger investment in test equipment and also in manufacturing test time.
If you have made changes to the pcb layout (or components) then it may be necessary to recalibrate. One way to check this is to follow the instructions in the application note WICED-MFG202-R.pdf to check the accuracy of the transmit power.
The application note WICED-MFG202-R is provided as part of the SDK. Please open SDK and navigate to the folderWiced-SDK/doc/ on the left hand side of the screen.
David Amour is spot on as to one of the advantages of using modules instead of chips. Typically the break even point in the decision between chip down and modules is ~200K pcs, and even then remember you are tying up your engineering resource during that time.
Radio development tends to be a lot more complex and costly than people imagine which is why companies that develop pre-certified modules have dialed in a business and enable faster time to market for people trying to get products out the door.
Here is a useful link for you: http://ack.me/products/Wi_Fi_Modules