I spent some time this morning experimenting with Concepts for the iPad, looking at how the different tools worked with various settings. Concepts offers vector versions of markers and various types of pens. The problem I have is getting the line widths to vary the way I want it to. There are also options for smoothing the lines, but I don’t really have the hang of that yet.
I do have a pressure sensative stylus for the iPad, so I will try that next.