Think twice before you buy the Edimax EW-7811Un dongle

This is just a complaint...
I think everyone who is thinking of buying a tiny Wi-Fi dongle should really think twice, especially those who is planning to use it on a Linux machine.

Edimax EW-7811Un

During the past three years working with it I got mostly just headaches.
It is slow (approximately 20 Mbps in my case) and it creates a lot of compatibility issues with the built-in Wi-Fi driver of Raspbian, Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and CentOS 7.

You are worth a better dongle.