I think mainly that it was bad resolution on the z axis. My print quality was bad and that turned out to be the extruder motor. I had fitted a 1.8 degree motor which was a little weak so I swapped it out for a stronger one which was also a 0.9 degree step....huge difference in quality! I think that having such a large amount of settings to get right on a new machine causes some confusion, also being a senior citizen can be a handicap.
Cheers!