I’m was a regular for the sugarcane, but moved to the Swiss water more recently. I was under the impression that finer grind and higher temperature was better. Can’t remember the details for light Vs dark roast..although I remember a study saying 96deg was the sweet spot (although no more than that).. That said I am unsure and in the process of beginning to experiment.
In parallel now have the duetto active in the office (mythos grinder) and Evo leva in the kitchen (with niche). Finding the Evo much more forgiving and better tasting, but slightly prettier crema on the duetto which is at a lower temperature I think. Too many variables really, occasionally chucking in some caffeine just to keep myself unbalanced!
@DenisS is the expert on light/dark/temperature I think he detailed at some length in the old forum in the Evo section at one point