Nice!
One question thou:
Do you use increased weight values when units are moving uphil?
If you take a look at first units path you see that somwhere in the middle of the map units path goes upwards on the hill and then even backway a litle.
Now this could be caused by lack of increased weight when going uphil since destination was much higher (heuristic estimate distance of those bocks to goal was actually closer) or some error in pathfinding algorithm implementation (wrong node selected for moving forward).