The way our company chose to create human-readable XML is to serialize strings instead of doubles or floats.  We used a stringstream with std::setprecision to get a certain number of decimal places.  The number has a chance of being slightly different after de-serialization and pulling it out of the stringstream, just like the old serialization method.  This is okay for us, as we need human-readable XML more than exact round tripping.

Hope this helps.