The following settings are recommended up to CATIA V5R24 (V5-6R2014) (Dassault) and NX 11

CATIA V5 (Dassault) – System

• Model should be cleaned of all unlinked information
• Delete unused elements from the NOSHOW area.

CATIA V5 (Dassault) - STEP Preprocessor

• Recommended settings in the STEP export options (Tools -> Options...-> Compatibility…-> STEP) :
• Choose the respective Application Protocol (AP): AP203, AP242 or AP214 (recommended).
• When exporting assemblies choose One Step File, because CC6 (External references) is not supported from all STEP processors.
• Do not export the NO SHOW area (set Export all entities: off).
• Optionally define the Header of STEP file.
• Validation properties are supported.
• If export a CATProduct:
• The option "work with cache system" has to be switched off (Tools -> Options -> Infrastructure -> Cache Management)
• The root node has to be selected, otherwise only the node of the CATPart will be exported

STEP File

• In the filename syntax special characters (especially / * % ) or umlauts must be avoided.

NX - STEP Postprocessor

• Start the external STEP postprocessor with Translator -> STEP AP214 and select Import.
• Select Edit -> Settings and define the options:
• (or interactive from NX 8.5) To export a STEP File choose File -> Import ->STEP203 or STEP214.
• Object Types: One or more of the options Solid, Product Data, Surface and Wireframe (depending on model).
• Recommended is to use the default settings in menu Translation Control (Tolerant Modeling).
• A*.log and a *.def file will be created in the same directory as the imported models. 
• Validation properties are supported.

NX – System

• Shaded view is helpful for a first impression of model quality.
• By choosing the menu option: Information -> Object -> Type -> Solid Body -> Select all correctly transferred solids are identified with red color. (Same way with other model types).
• By choosing the menu option Information -> Object -> Objects -> Select all after choosing the filter for Solid Body in Information -> Object -> Filters -> Type Filter correctly transferred solids are identified with red color. (Same way with other model types).