i've went the backbone/knockout/angular route and i think all of them works great for simple things. but if your project gets a bit more complex (or where your code-base changes frequently), you'll start running into all kinds of problems. yes, you can usually hack around them after several exchanges on the mailinglists/irc, but very time-consuming nevertheless.

now, i'm back to plain javascript/jquery. i run into less headaches and more control, therefore more productive. my gripe is the same as op, the "magic" is what throws me off. angular is a bit too buggy, last i used was 6 months ago, and still lot of things they didn't support like proper callbacks upon rendering, etc ...

basically something really easy to do in plain js, becomes like a rubik's cube with all the magic going on. just be prepared to write a lot of extra code/hacks/patches for certain things to just "work" if you decide to go the i.e; angular route. but don't say i didn't warn you :)