IE11 reporting incorrect scale for touch width/height

Hi,
On IE11 on my SurfaceRT, the reported width and height values seem way too
small to be correct in terms of CSS pixels (as specified by the standard
and MSDN document).  Eg. with  http://www.rbyers.net/eventTest.html I
typically see values of width/height=1, but with a really fat finger I can
get values up to 5.

Is this just a bug in IE or the Surface?  Are any other devices known to
properly support touch dimensions with pointer events?  Any known web sites
that use this information?

I ask because I'm a little nervous to have Polymer+Chrome accurately report
width/height values if there are sites already compensating for the scale
in IE not matching the documentation.

Thanks,
   Rick