Is 々 commonly used and recognised by Chinese people?
It's not common in publications or daily writings nowadays, but all people can recognize it. It often appears in the calligraphies or on posters. The writing space of those media is precious.

And some teachers like to use it in class. 

BTW, the Chinese prefer the right one, the cursive style, in their handwriting.

The source of it: cursive 仝, the variation of 同.