No, not really. They are finicky to use, particularly if you want to hit medium or heavy mechs, because assaults keep setting off the field early. It's better to use pre-positioned standard fields. That way you know where they are, and the opponent doesn't. There are a finite number of good positions on a battletech map, so you almost always know where the enemy will go during the course of the battle. They may not be too terribly effective against heavier mechs, but they can cream the light ones.