Interesting thing happened today. Keep in mind that I am a beginner, even though for many years, I had a Saeco Aroma (with pressurized portafilter). I also know that you are not an advocate of the guidelines, but I think that it is a good starting point for a beginner. Keeping in mind that I had the time of 38 seconds (maybe 36, maybe 40) where the Lattes seemed to be where I liked them, with the exception that I would want my Latte a bit less strong (less Espresso). I have been putting 17.5 grams in my 18 gram basket and pulling a 2oz. shot at the 38 seconds quoted. Why 17.5 and not 18? I have two of the same baskets and one works beautifully at 18 grams, but the other consistently makes the puck stick to the shower screen. I tried 17.5 grams and both are happy. Anyway, just for laughs, I tried the Clive Coffee shot instructions to get 30 grams output from 18 grams (but with 17.5 grams in my basket) in 25-30 seconds. I "let it fly" at my previous grinder setting and got 30 grams in 25 seconds. On top of that, the 30 grams of Espresso is less than the 2 oz. shot I was pulling before, and it gave me the less strong Latte taste I was looking for. I am now much closer to what I wanted and will tune it based on where I just got these results.
Danny