Circus Ponies Notebook is an excellent program, and has more depth than the others, and is $49. But you may find it in a bundle somewhere - which I did whole bundle for 10 apps was $49. I have been using every day since I purchased it.
I would endorse Circus Ponies Notebook for university use. The folks are Circus Ponies are very helpful and have answered a number of questions I had when I started using it a couple of years ago. I had personal e-mail replies about formatting issues, me working out what you can and can't do. They also have plenty of video tutorials on their own site,
http://www.circusponies.com/purchase-notebook/ . Also, there are many tutorials of youtube...
.... They offer a student price for the licence, currently
$29.95.
The Notebook is very powerful, yet easy to use. You can pull files right into the notebook pages; PDF files, that your teachers put up on Uni web pages... audio files, which I record. O can put these straight into notebook pages and add by own notes... you can have collapsing headers; hiding information until you need it. You can include pages of different types, including cornel revision styles..
I have been using it solidly for the last month as I have been preparing for exams... it takes the hard work out or organising data of different types, all in one place; text, PDF; audio video.... you can clip data straight from web-pages... It is a truly powerful tool, which goes at your pace....
No I don't work for Circus Ponies, but I am a fan!