A PC board can also be run on a twelve volt power supply, using an inverter, depending on your region either 220v or 110v.
Built into a waterproof case.
Does exactly the same thing as routerboard.
The only advantage of having a routerboard that I have noticed is power consumtion is less, and is more compact.
But if you have reliable power source then and old 486 or pentium board with small hard drive could come in handy.
I prefer using RB instead of PC due to power usage, as we have alot of problems with our power provider.
But hey, at least you know it works