I am getting ready to start a little Android development and need to choose a language.  I know Python but would have to learn Java.  I'd like to know from those of you who are using Python on Android what the limitations are.  Also, are there any benefits over Java?
I have developed Android Apps on the market, coded in Python.  Downsides: 

Thus far my users must download the interpreter as well, but they are immediately prompted to do so. (UPDATE: See comment below.)
The script does not exit properly, so I include a webView page that asks them to goto:Settings:Apps:ForceClose if this issue occurs.
What are the limitations of Python on Android?