I don't think this will replace anything or at least it shouldn't. If you have Modo or Mudbox or Zbrush and are proficient and comfortable in them, then there might not be anything useful for you in this application. It depends on what your needs and workflow are. I think the bottom line for this app is you can't beat what it can do for the price. That's reason enough to get excited.

For me personally, I have purchased tools just because of one of the things it can do, that my others cannot or not do as well. Of course, there's a lot of redundancy in my toolbox but what the hey.

For instance, Zbrush 3.1 is so unstable on my machine, I can't keep it running and went back to using Zbrush 2. But I usually only use it for texture generation and playing with zspheres.

Silo I use for basic forms.  Hexagon has a great decimator for keeping hard edges.  Curvy3d is the ultimate lathe. MOI is great for nurbs. AC3D I bought just to have the instant greeble maker.  Archipelis is my sketch modeler of choice for implicit surfaces. Metasequoia I keep as the ultimate metablob modeler. And it keeps going this way for all my tools, 3d and 2d.

So it all is just relative and depends on individual needs and preferences and what you are successful in.

So whatever you use, I wish everyone success!!

M