Downloaded and ran through all three.

Assembly is a rooting tooting death match where basically the only strategy is run and gun and chuck grenades.

Orbital is a little bit of a maze of goodness. This could be a fun map however with lots of boxes to hide/protect yourself. I played multi-flag and it was enjoyable. The low ceilings don't allow for high jumps and protection.

Sandbox...Haven't played this one yet, but stay the FUCK away from the vehicles. There are 2 constant spawning rocket launchers with 4 rockets, 2 missile pods on each side, 2 shields, and a center post with an overshield taunting you. Fully customizable though which could provide for some fun variants. They have grifball as one of the map varieties.