A while back we moved from being a Source mod to stand-alone UDK game. This has been the best choice we have ever made, we can tell you the progression is by far faster so pictures will be uploaded.
Update:
So what we have been working with is mostly the environment, buildings, trees, street-lamp's etc. adding them into the game even before making the textures so we can work side by side with the level-design. Level-designing can be very tricky which is why we currently focusing on one great/perfect map we can cut into a smaller map for other game mode(s). The map will be maxed on our own realistic mode but also the standard team-deathmatch mode.