Directions to Abbey Wood

Its been many years since we last went to Abbey Wood but looking at the CC directions they don't seem to have changed a lot. However looking at Google Earth it would seem that leaving the M25 just south of the Dartford Crossing and heading for Erith and Thamesmead using Yarnton Way and Harrow Manor Way seems to be an easier route albeit a little longer. Can anyone compare the two or point out problems that might not be obvious from Google Earth?

Thanks

David