Advantage one. I can place them on building tops.
Advantage two. I can lay them after deployment.
Advantage three. I can lay mine in my zone to protect me from Fidays, Van Zane, and AD troops.
Advantage four. I can lay more mines in my opponents' way later in the game.
Mines do not react to other mines, but they help me control the board where I like them
And no, Points are not awarded for my mines, just the neutral mines.