Flashing a router with Open Source firmware voids the warranty with the original manufacturer. We offer our own 90 Day Warranty out of pocket with additional add-on options, including the aid of our on-site US-based Support Team, that would not be received if you "flashed on your own".
Our routers include this advanced US based support to help integrate VPN service and advanced connectivity on your router with a variety of providers. The VPN service is sold separately but this integration process can be complicated and confusing and we take any worries away from customers who want the benefits but are not technically proficient with high-end networking equipment.
Flashing a router with DD-WRT or Tomato firmware turns the device into a FlashRouter as opposed to being a Netgear or Linksys router. Using Open Source firmware allows for an additional slew of features that are not available using the frankly lackluster firmware that routers arrive out of the box with.