We have PCB layout (with Gerber export, which actually passes all BatchPCB or Eurocircuit DRC checks) and allow other circuits to be included as modules. I think this is a major difference as you can actually design something and have it fabricated. And the modular design flow allows you to "stand on the shoulders of giants". With the right modules, you don't need to be an expert anymore to design electronics.

Upverter has a nicer schematic editor and more social features, but doesn't have any PCB layout capabilities (at this time, at least.)