Yeah, I always found my best Faemina shots were 14g and no second pull. Even though the 51mm basket could easily accommodate an 18g dose, it always presented headroom issues and the shots lacked clarity compared to the lower dose, single pull versions.

I have had three different Faeminas - one first gen and two second gens - and the groups all behaved very differently in terms of flow rate and shot volume.

A single pull makes a huge difference in water temp. Italian standards dictate the temp of the drink in a preheated cup at 67C +-3C (153F +-5F). My best tasting single pulls will usually be very close to this. Double pulls tend to raise the temp in the cup by a lot. Very easy to measure the finished espresso temp with an infrared thermometer gun. I adjusted machine pressure to achieve this with every shot.