In summary, it's not perfect, but it's better than not having it.
For instance, it chokes pretty hard on SQL Alchemy scoped_sessiosn and declarative_base(), and doesn't seem to resepect the sqlalchemy package.
That said, it works pretty well for just about everything else.
As background, I'm running 32 python 2.7 (64 bit wasn't playing nice with pyodbc)
Because of the inherent 'gotchas' with the plugin, it can seem as if it's not functioning.
A quick way to check and see if it's working is to create a new file with 'python' selected as the syntax.
Then, in the file, type "from" and hit space.
In the bottom gutter, if working, you should see modules being scanned.
After the modules finish scanning you should see a list of modules in a popup, you can import from.
As python's a dynamic language, there will exists cases where the parser won't be able to determine what type the object you're working with is -- in these cases you will not get autocomplete suggestions.
Finally, one additional sanity check I can recommend that gave me peace of mind was to cross-validate the auto-suggest in KomodoEdit. If the snippet you're working with also fails in Komodo, there's not much to be done from the plugin-side, as it references the Komodo library.