I do not use the sun object, but I don't try to make the render super realistic either. I wouldn't use both the cinerender sun and the object though, that seems a bit double. Remember to turn on the lights in cinerender to make use of it.
I think the sun object is more for wanting to have noise / visible light / god beams sort of thing with effects (not sure if all of them are available).
If you just want a bit brighter look, turn the sun azimuth so that it shines on both visible facades and set the altitude around 55 degrees. Should work with any of the presets. I just did a detailed write up of how I tweak the lowest quality physical renderer preset to give a quick decent render here:
https://archicad-talk.graphisoft.com/viewtopic.php?f=3&t=61848
Erwin Edel, Project Lead, Leloup Architecten
www.leloup.nlArchiCAD 9-26NED FULL
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