html - Closing empty tags: XHTML5 or HTML5? Why one over the other?

After reading extensively about HTML5 and XHTML5 and after
reading this post: href="https://stackoverflow.com/questions/3558119/are-non-void-self-closing-tags-valid-in-html5?rq=1">Are
(non-void) self-closing tags valid in HTML5? , I have got a very simple
question:

"Is there a reason why it would be
good to serialise HTML5 as XML?"

I
understand:

• the
  differences between HTML, XHTML, XML and HTML5


• that it's
  good practice to nest elements correctly, use lower case letters, quote attributes,
  close tags etc...


• that HTML5 has no DTD while XHTML has
  got a DTD and an XML parse



• that if I specify a
  page as XHTML5 (HTML5 doctype + XHTML schema) some browsers might not process the page
  for minor errors
  etc...

So the question
is:

"In which case would it be good to follow
very strict XML rules when doing an HTML5
page?"

Above all when it comes to things
like

1) The void
elements

            src="asdsad.jpg" /> compared with 

            compared with 
 comparted with
            

2)
Checked, download etc..
like

            name="vehicle" value="Car" checked> VS
            name="vehicle" value="Car" checked="checked"
            />

Should
I just write following the HTML5 standard and implement as much common sense as possible
(lower case, good nesting) or is there A GOOD REASON for a standard company website to
be coded in XHTML5?