Depending on the coffee I use, I notice a big (~5g) difference in volume before my portafilter basket is filled. With some coffees I'm barely able to get 19g into my 21g+ basket, and with others I can easily go over 24g without any spilling.
What I'm wondering is, do people usually just aim for the dose weight the portafilter basket maker designed it for, or do you go with what fills it up? Do you vary based on the coffee up or down in the dose, or again, aim for a static dose weight regardless of coffee?
Thanks