Years ago, I got a degree in EE. I used this degree in my career for several years, then hit a dry spell. To make myself more marketable, I got a second degree in Digital Media (DM), with an emphasis on audio engineering and video production. Ironically, the best university around for both these degrees was the same one.
Fast forward a few more years, and I landed a job at at my Alma Mater as an adjunct instructor. Until this, I hadn't needed a schematic cad system in ages, not since the days of Orcad and Pspice for DOS. Now, however I suddenly found myself needing one again. One of the classes I've been given to teach is an electronics for audio engineers class. This class didn't exist when I got my DM degree. Somehow, the department seems to think that I'm the only teacher they have that's qualified to teach this, right down to creating the curriculum!
It's FREE. It is fairly intuitive to learn and use. It has a decent part creation / editing tool.
Importing libraries from other, commercial systems is not easy.