I'm still getting used to using the iPad Pro for drawing, so I spent some time on my flight to Anaheim doodling. I am amazed at how fun this tool really is! I have a long way to go, but I'm starting to get the hang of the brushes, layers, etc.
I spend a lot of time on airplanes, which means I used to waste a lot of time on airplanes with my old iPad that was little more than a kindle in my hands... I actually enjoyed the flights as I poked away at the drawing. I can picture this being a really useful tool, and pretty enjoyable way to kill some guilt-free time.
Here's the deal on smooth lines - you can adjust the streamline setting which applies some elasticity and tension to the lines which smoothes them a bit. Shaky lines are very much apparent in a hard, black line with sharp edges, and much less apparent with a grainy pencil with edges that aren't so crisp. I actually prefer the softer pencil brushes because i like that look. But for transferring you'll probably want as sharp and black a line as possible.
These are the custom brushes I use. The outliner is pretty shaky. The engraving brush is much smoother and good for most of this type of work, but it's useless for other things. Try signing your name with it and you'll see what I mean. Some users like the tension on the line and some don't, or like less tension. That can be adjusted of course.