Reasons not to use xml.etree.ElementTree:

1) http://docs.python.org/2/library/xml.etree.elementtree.html#module-xml.etree.ElementTree says it's insecure:

> Warning
The XML modules are not secure against erroneous or maliciously constructed data. If you need to parse untrusted or unauthenticated data see XML vulnerabilities.

2) it's a python implementation, which means it's slower than lxml or xml.etree.cElementTree

3) lxml works. Don't fix what isn't broken.