Why not just use a pen and a spiral notebook? (Scan the pages in later.) They're:
1. lightweight 2. cheap as dirt 3. don't need a charger 4. battery never runs out 5. can drop it with impunity 6. nobody is going to steal it 7. not distracting to the guy behind you 8. no temptation to surf the internet during class 9. no user interface issues 10. no buggy software
Then they got VC money, and like so many companies, it all went terribly wrong. They get an absurd amount of money for a service that stores data and syncs it in a cloud (a generic concept better executed by competitors) and have to somehow generate revenue to meet this valuation. So now all kinds of functionality that the users originally didn't need or want starts accumulating in the application. This introduces bloat, bugs, and UI cruft. It does chat now (lolwut). I feel they have been deliberately fighting Zawinski's Law, but it will come, it's just a matter of time.
I would welcome any suggestions for another service that is basically what Evernote 2 or 3 was.
I can't believe no one's mentioned it yet in all these comments. I've been using it for 7 years and I've never lost data. The worst bug I've hit was the search feature has sometimes not reported every match across all notebooks correctly, but I haven't hit that since upgrading to the 2013 version. Everything's cloud persisted and cached locally, so if you're using it across multiple devices (I use it across phone, tablet, and 3 PCs) you should have plenty of redundancy. OneNote notebooks are single files, so you could map them to dropbox, but I've been happy enough keeping mine in OneDrive.
I use OneDrive because of its superior features over Evernote - fantastic outlining support (shared engine MSWord has been using for years), hierarchical organization (notebooks > tabs > pages > freeform sections), being able to embed arbitrary files, fast global search. Haven't used Evernote in a while though so maybe it's improved on these fronts.
I'm using it on Windows (desktop version, not the app) and Android and it works pretty well.
The OSX native app seems to have parity more or less with the Windows one. I use it at work and haven't had any issues.