@gaieus said:
The very problem with these questions is that there is (probably) no person who uses all of these renderers to be able to correctly answer your question.
I wouldn't despair about the usefulness of these threads. I've read through many of them and learned a lot.
I think the problem is the initial question that starts the topic tends to be too broad - i.e. can you make dazzling photoreal renders with this or that program? And the answer generally is - Yes, if you're Solo.
But my interest was in the opposite direction - let's say you have a client who announces that in an hour she is popping off to somewhere (Paris, Biarritz, Le Cote d'Azur, wherever they go) and you want to show her progress so she'll cut you a check before she leaves. You want to send her something in literally 15 minutes and you want it to be a bit better than the native SketchUp or Layout output. Some amongst us could do that in any program but most of us can't.
So, given that scenario the question becomes quite different. I followed up on the Twilight suggestion and found that it fit the bill pretty well.

No setup, no lights, no fussing at all. Now I understand that Twilight can probably generate much more spectacular results than this but that wasn't what I wanted to find out. Given the parameters of very low cost and as close to being a one button solution as is reasonable - what rendering programs fit that description?
So I have one good option as a result of starting this topic. I intend to try out Shaderlight and LightUp but during the week I didn't have the time to try out 3 different programs.