WRT firmware on Netgear DGND 3300 v2 :: Technical Issues

Have one of these (with the cool blue LEDs showing the antenna status) as a backup in case I need to swap the Billion out for testing.

As this router is end of life Netgear are of course not maintaining the firmware so it might have security flaws, etc.

Was thinking about flashing it with WRT or similar, anyone any experience of doing this with this router?

Virgin (ADSL) => Namesco => Newnet => O2 => Plusnet => Zen => Newnet => Zen => Freeola => Vivaciti (using O2 Wholesale DSL) => Xilo (C&W Wholesale) => Xilo (O2 Wholesale) => Xilo (TT Wholesale due to O2 Wholesale closure) => Zen LLU
Router: Billion 7800N
Note: I don't lay turf for anyone. astro or otherwise, all views and opinions expressed are my own based on experience.