You also get the resource packer which protects your assets (and it's better than using a free packer since it doesn't unpack stuff at runtime). Other differences are no splashscreen requirement, unlimited multiplayer features, inclusion of level editor, high resolution static shadows, customizable startup window, and when A7 ships you'll have access to the distribution manager (see last item in forecast), and the new BSP that will allow concave

There's more than enough reasons to own Pro than physics (well, A6 Pro) and render to texture. I still think Commercial is the best value for the money, but there are quite a few Pro features that are pretty important and worth the extra money if you need them.