Alternative to Autodesk Sketchbook Designer ?

Actually I downloaded the trial PRO version and it has the Vector function.
However, although I spent a good couple of hours, I feel the interface is very complicated. Also, I could not find the very handy functions SB had like trimming the vector lines, connecting them with radius. Maybe I need to spend more time but really I got lost on all these options.
SB had this nice spartan feeling. Minimal complexity with just the right tools.