RE: Linked Feature Definition Style File - SS4 and SS2

Ss4 is significantly different from Ss4. Ss3 and Ss4 are the initial releases of Open Roads as the successor to the three Bentley Civil products - InRoads GEOPAK and MX. Ss3 should not be used as once Ss4 was released, it fixed numerous flaws in Ss3.
So, what makes it so different? The Roadway Designer and Site Modeler have been replaced with new tools that run 100% inside of MicroStation, live in the DGN file. A Terrain Element has also been added that replaces DTM and TIN. And Civil Geometry - also live in the DGN file replaces ALG and GPK files, using MicroStation Elements with enhanced intelligence as alignments and profiles.
You can save back to the native products and import native product data into Ss4. Also, the XIN and D&C manager functions are mostly replaced by "linking" them to a DGNLIB (recommended) or the active file (last resort) which create Feature Definitions, managed in the Project Explorer (thanks to some additional Civil/Site/Survey tabs) which also work with Element Templates to drive the graphics.
I have both products (Ss2 and Ss4) installed on my PC, but I also use Power InRoads, which makes the dual use easier.