You can, of course, combine the two, and many designers do. The open source gEDA PCB package (and pcb-md) have an autorouter, but it is pretty simplistic. [VK5HSE] shows how you can use a few ...

He wrapped it all up by designing a PCB in gEDA PCB and having it sent off for production. As a testament to his attention to detail, everything mated up on the first try. [Maarten] is happy with ...