Hi Peter, well there is a difference between the methods.

That tool just combines all the polygons together into one big object - this leaves a bunch of polygons on the "inside" part of the mesh - it basically does not generate an object made out of one single connected skin.

In other words, it is not a totally clean single volume.

For some purposes like rendering where you aren't looking at the inside that is not a big deal. For other purposes like manufacturing, this kind of messy interior is a problem.

The 2d method would create a completely "clean" volume without extra pieces hanging around on the inside of it.

- Michael