in regard the comment about the Voice change on the ATIS, i couldnt comment about the Heathrow version, but at most airfields its an automated system using a computer synthesised voice, that automatically produces the atis from the various sensors and computer equipment, the system off has also various stored messages built into it(for things that might need adding occasionally - such as windshear etc) However when there is something a little more unique to be added like a blocked taxiway etc, this is normally actualy recorded there and then by an Assistant and added to the standard message, so this will result in a sudden change in voice on the ATIS from the rest of the weather info. Does make it sound a bit strange, but in some ways highlights this unusual information, that may as yet not been notamed, or the crews even had chance to see a NOTAM regarding it as it may have occured whilst they were inflight.
ATIS messages are oftne criticised for their length, as others have pointed out, it needs to contain enough but not too much information that it lost in the gabble.