Is a USB Wireless Network Adapter as powerful and reliable as using a PCI Slot Wireless Network Card?

I am considering setting up a wireless network within my home and i have done some research into it and found that a lot of networking kits you buy nowadays only do the Router+USB Network Dongle, are the Dongles as powerful as the PCI Slot Cards i am used to using?, any help would be great.

They are the same. They will both connect at a maximum speed of 54 mbs. Although a PCI slot is faster than a Usb Port as far as getting the data to the processor.

PCI slots,parallel ports, video ports-network PCI adapter A+G, dead end of HP6930p