Which step file is the right one in KiCad?

[Lutz_Muller]

Please indicate the line number from above.

[eelik]

AP203 has less features, for example no colors (you can do a google search for "ap203 ap214). Use 214 if it works and you are otherwise unsure.

[der.ule]

I mostly use AP214 and work well, haven’t had problems so far.

[poco]

Me too, choosing only ap214 when asked.

[GerardFX]

As mentioned to be preferred when available (normally should work, and lighter than wrl file…).
Don’t know presently for the December’s V6 (by still using V5).