Either iPhoto or Aperture can directly read/download images placed on iCloud by an iOS device. There is no need to involve any internet browser. How long the download takes depends on your internet connection but generally it is reasonably fast. At the moment I have 799 images in iCloud and the thumbnails appear almost instantly on opening either application. Opening the full image for editing takes roughly ½ second.

In either iPhoto or Aperture iCloud appears as a shared device and the downloads are by default assembled into Events entitled "month year Photo Stream". Of course once you have them in iPhoto or Aperture you can move the images into Events as you like.

Personally I never take any special action to upload or download images from my iDevices. I take a picture on the iPhone and when I open iPhoto or Aperture i expect it to be there and it is.

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein