I work at a university in the UK, and we are stuck with Orcad as someone arranged a good deal many years ago, so we have more seats then we could ever use. Management sees changing package as "buying something we already have again", and its hard to change that mentality.
I have used OSS offerings, Orcad, and Altium. I would personally pick Altium for teaching, mainly because its UI is quite discoverable, it has some nice offerings for embedded and FPGA development (something we teach our students), its training materials are good, and it has source control integration. Its not perfect, but its the best ive found so far.
The other plus of Altium is that we use Solidworks for mechanical CAD, and the back and forth interop would be quite helpful for mechatronic projects.
As for djsb's comment, if all you need can be achieved with kicad then great, but at our Uni at least, that would not cover everyone. A licence for Altium is around the £1k mark for universities in singles, and I believe Orcad was much less than that when we got onboard, and as a researcher, if altium shaves 5 days off pcb design time over 4 years, then that has paid for the seat in costs.