In determining the preferableness of fuel and wick types, the שולחן ערוך and רמ"א refer to light "hanging on wicks nicely" and the possibility of candle light being "clean" and "clear". What physical states of burning wick/fuel do these phrases describe?
Is a comparison of light "clarity" or the other parameters listed above relevant with the modern home pyrotechnology of today or is it a moot point because the standard materials used automatically exceed the necessary threshholds?
(This question is motivated by a cryptic but direct פסק I got recently from a prominent American פוסק that, as far as the רמ"א's opinion is concerned, wax candle flames are not clearer than oil flames.)