Frustrated by the software limitations of your router? Replacing it with the Linux-powered DD-WRT firmware can be a big upgrade. Maybe you want to use an old router as a second access point for your home network or as a Wi-Fi extender. Maybe you want more precise control over how your bandwidth is used so you can prioritize bandwidth for your gaming sessions, or perhaps you hate the firmware that came with your router and prefer something with more features.
source: Digital Trends