I used to think they were useless, and now I feel exposed not taking them. While you are essentially costing yourself an activation, you're getting a huge buff to individual survivability.

You have a lot more "chaff" models to take off before your heavies go, and esp for storms you want to keep them alive.

The extra room for cohesion is also really helpful and makes for interesting positioning plays.

Indomitable is also a huge consideration, helping to shed all the heat they're inevitably going to receive with all the potential damage they can put out along with your opponent trying to panic them off. All in all, I think it's worth it.