I've been following this project for quite a while. It's a very nice little modeler that was built to please the Silo crowd. Originally it was called VoidWorld, but it's since been renamed NVil (anvil).

For the longest time it was available for free as a beta, but he's now selling it.... for $79.

http://digitalfossils.com/

Head to the forums for more info: http://voidworld.cmcproductions.co.uk/

Overall it's very fast, and does exactly what a modeler should do. The developer reminds me a lot of Andrew Shpagin the developer of 3D Coat, in that he is extremely quick to reply to feature requests and releases several updates per month.

I d/l and played with it a bit. Why should I pay for this when Blender is free?

Well, as I said, NVil was created for people who were using Silo and were disappointed in how it stopped being developed. It has a 3DCoat connection, so you can use NVil for the base mesh and 3DC for sculpting & painting.

Plus, it's $79, which is less than most plugins for Softimage.

As far as why to use it versus Blender, that's a bit of a non sequitur. You could ask the same question about anything. Why pay for Softimage when you can get Blender for free? Why pay for any 3D software when you can get Blender for free?

I tend to want to support new projects from small developers. It ensures there's at least a few options other than Autodesk.

-Paul