AutoCAD Inventor :: Create Surface Bodies From Multiple Faces?

I've currently written an application for SolidWorks that reads file that geometry in the form of faces (ie. 3 or 4 double values that represent triangular and quadirilateral faces).  I am trying to create the same application to work for Autodesk Inventor, but I am having some issues.

First, I am basing my code off from the examples given in the help files.  There's a lot of pointers to objects being to get to the Face creation portion, this seems to be slowing my appliation down considerable compared to the SolidWorks counterpart.  SolidWorks API has a modelling method called CreatePlanarSurfaceDLL that allows me to provide an array of doubles representing the vertex points in order (x, y, Z) for each point, so the array looks like this for a triangle (P1.X, P1.Y, P1.Z, P2.X, P2.Y, P2.Z, P3.X, P3.Y, P3.Z).  Is there anything similar in the Inventor API to simply the process?

Secondly, when using the example, they all have a known "shape" and therefor there are a definied number of vertices, edges, faces, etc.  And when adding the faces, the known points / vertices are used.  In my case, each face contains information for it's 3 or 4 vertices.  I created these using the prescribed methods, but when the final surface body feature is created, and a repair is performed on it, it shows a lot of duplicate edges and vertices.  Do I need to take the time and filter out all of the duplicate vertices, and point to a single vertex that may represent a vertext used by up to 3 or 4 faces?