I ran a few rounds on each side to give it a little test drive and it seems pretty solid to me.
The only thing that came to mind after playing for awhile is that the engineers seem to just get tangled up in a bloodbath over who gets to keep the command post when a few creatively placed mines could be just as useful.
For example - in front of the door to the access key house, at the base of the wall where the covert ops like to jump down after stealing it (assuming they live
) or maybe just in front of the rubble that one uses as stairs to get into the command post hut. If you wanted to get really evil you could even make them drop a few around the keyhole at the purification door.
Its just a thought, and all it would do really is give the engies something to do rather than lob themselves into the oncoming stream of troops and probably toughen the defense some. Overall it could be just as good without the use of this suggestion, if you ask me, but it might make things a little more interesting.