Well, I'm not aware of many people who use 4DOM these days, and if that's what it's meant to refer to, maybe that should be made more obvious, because it currently is not at all. Even cDomlette uses only half of the memory according to

http://effbot.org/zone/celementtree.htm

When you say that the description is "factually correct", that does by no means imply that the average reader will understand how it's meant. My point is that almost everyone who reads this will draw the wrong conclusions.

Also, when you say "lower footprint", that does not yet make it "light weight" in any way. It still uses something like ten times as much memory as cElementTree or lxml in Python 2 (and likely much more than even that in Python 3), and still something like 4-5 times as much as plain Python ElementTree. That's a huge difference.

What about this phrasing then:

"""
MiniDOM has a smaller memory footprint than some of the other DOM compliant implementations for Python (such as 4DOM), but uses about 10x more memory than the faster and simpler xml.etree.cElementTree module.
"""