This is a map I've been chipping at on and off for a while (my day time job tends to get in the way) Rushbase Download - V11.1
I made a trap room for the Double Damage. I'm currently working on meshing the map out.
Epic gave me a great review, and hosted the map on their official servers.
I will keep the download link updated as it progresses.
Original post on the Epic Forum
Enjoy!