Here's a new twist on the classic objective mission. The other day we were using the Planetstrike guns as objectives, and I thought, "What if the guns were active?"
We tested it, and it makes the game different, as instead of making a last turn grab for objectives, it becomes advantageous to hold them as it increases your firepower. We played this game with the Solifugid campaign rules, with each gun guarding a tunnel entrance (which was the actual objective). The winner gets to reroll reserves in the next tunnel battle, since they control more access points.
The mission is played exactly as capture and control, but with the following exceptions.
Setup: After placing terrain, place 5 gun turrets on the battle field. These weapons have the same stats as the Planetstrike guns (quad gun and lascannon, minus the automated weapon and interceptor status). One should be placed in the center, and the rest in each table quarter 24" away from the center gun.
Firing the Guns: A squad within 2" of a gun may fire it during their shooting phase. The model firing the gun may fire at a separate target than the rest of the squad.
Shooting at the Guns: The gun has an AV of 10. Any glancing or penetrating hit will destroy it. The gun is treated as an extra squad member for the purpose of allocating hits (I chose this instead of standard artillery rules because it makes more sense in this situation). If the gun is destroyed, it still counts as an objective (as the objective is actually the tunnel entrance).
It's really just a simple twist on the old mission. I have found with homebrew rules that the best way to go is to keep it simple.