Pros:

+Awesome building idea in sandbox.
+Mutigen idea is the best.
+The bases coming up were fun.
+Jimmy Gibbs Jr.!

Cons:

-Cant build high in sandbox (want to be in the tower with louis and survive)
-Building in sandbox is hard.
-Turrets attack nothing exept survivours (one killed francis in his tower).
-You can survive the base attacks with players by jumping on top of the tower of the command base (hiring, etc).

Conclusion:

These maps are fun to play, and challenging at the same time. I liked the idea of Jimmy Gibbs Jr. with his car, and the heli of helicopter dude was awesomesauce. I had a lot of fun with the mutagens in the base map.

I only want you to fix that building stuff, and that if you place it wrong, you can replace it and that the defencive props and all that stuff gets "welded" so you can build in heights too.

The building idea can also be found at a new (not yet released) map called "lets build another rocket" which has the same building stuff, but you can build towards the sky.

Conclusion: Very, very nice maps!