I agree. I found the documentation very difficult to understand.  The term "top-level" can be confusing. Consider instead something like "search the entire tree".

A few other comments about the documentation of findtext:

findtext(path[, default])
    ... Returns the text content of the first matching element, or the default value no element was found...

The first comma (,) following 'element' is unnecessary and in fact incorrect. Also, 'if' is missing. Sentence should read "Returns the text content of the first matching element or the default value if no element was found."

findtext(path[, default])
    ... Note that if the element has is found, but has no text content, this method returns an empty string.

Again, an unnecessary comma exist and there's an extra word. Should read, "Note that if the element is found but has no text content, this method returns an empty string."

Note, the wording changes should be made. The other suggestions should be considered soft suggestions and merely my preference.