I've found 3 row-level permission solutions for Django 1.2+
Could someone tell if there is any recommended more than the others, what are their main differences, etc.?
I'll start this by saying we use none of these for object level permission - we use our own custom method and I really wish we hadn't. If you can avoid object level permissions at all, do so, they are a pain to organise.
This is how I evaluate the 3 apps you've mentioned.
Active Development:
API
The above are in order by the way.
I'd recommend guardian purely on API alone, but the fact that it is still being developed where the others aren't usually means a big win.