Our tool can be configured to source parts from specific vendors, such as Digi-Key and Mouser, etc.
We plan to replace most of the needs for prototyping. But there is still about a 3-4 day turn to get your boards back from the fab.
If you have all the parts already lying around, and a breadboard handy, then you could get a breadboard design up faster than you could with our service.
We have Wyisywig tools internally for help during placing / inspecting the board shapes / verifying package footprints etc.