The main issue with USB is most are designed for the portable market. This means physical size and battery/power usage is trade off for performance/signal power. Those very tiny USB module also have very small antenna and they sit almost inside a large metal case that blocks signals.
They make USB devices that perform as well as internal cards but almost all of these are fairly large and are connected via a USB cable to get it away from the computer case.
For a desktop machine you want to always use ethernet if that is a option and then consider powerline units. This is more of a concern if you are playing online games, normal surfing and netflix works well on most wiif.