I agree with the Gcode comment. I think the early users of 3dprinting can handle the tinkering of STL files and I like to see the file first and check scale etc before I print. Also I can control the speed and temp of my printer mid print so I start of slow and hot for the first layer and the increase the speed of the print and reduce the temp by 20 degree. This is all great if your into this level of printing, however I feel that to get really mainstream then this will slowly die out and be replaced with print codes. Will the mass consumer really accept having to wait for slicing. If it is done for you does that not make the user experience more seamless?