Whether 2.4 GHz or 5 GHz band can make a big difference in the purchase decision, as these are directly related to the performance of the wifi stick. A big problem in confined spaces can be the frequency band on which Wifi adapters transmit.
A distinction is made here between 2.4 GHz and 5 GHz. For so-called Wifi-N sticks, a frequency band of 2.4 GHz is standard, but can usually also be switched to 5 GHz. The prerequisite is a router that can do this.
The problem with the smaller frequency band is that other signals can interfere with the connection.
Other Wifi networks or Bluetooth devices then cause problems for the home network. With Wifi AC sticks, on the other hand, the 5 GHz frequency band is used as standard. This has the advantage that the wireless devices share their frequencies better and can get in each other's way less.
With the 2.4 GHz band, the range may not be sufficient and you need an additional repeater to amplify the signal transmission throughout the home. This problem can often also be circumvented by using a 5 GHz stick.
Devices with a 2.4 GHz band are usually also much slower. They often only achieve a speed of 150 MBit/s, while other devices also manage well over 300 or 400 Mbit/s. The actual speed can then be checked quite easily via external programmes.
It is best if the selected Wlan stick supports both frequency bands.