[waterlesscloud]

I've done several of these online courses so far.

The Udacity ones are definitely the easiest of the bunch. I think they aim to be. That's ok, it seems to be their market, at least at the moment.

Cousera courses seem to be more challenging, though I suspect they still fall somewhat short of the demands of the actual Stanford classes. But I get more out of them and prefer them to the Udacity classes.

The best class, by far, was the MITx Circuits class. I found it very demanding and felt a genuine sense of accomplishment when I completed it. Again, I'm sure it wasn't as tough as the actual MIT class since the exams were longer and open book, but it was by no stretch of the imagination easy.

If all the classes at the various options were like the ones that have completed thus far, I'd pick the EDx (formerly MITx) courses hands down.