"Five" -- Map-Specific Strategies
Stick To Your Guns
First, the good news. There are no hellhound rounds on "Five" to worry about. Instead you've got a scientist zombie who can't even hurt you. What he does, however, is much, much worse. Appearing less frequently than the hellhounds, this guy will appear all by his lonesome. It's possible to kill him, but he soaks up a TON of damage (four players emptying all of their assault rifle rounds into a scientist MIGHT kill it, with enough headshots). Here's where it gets tricky: if this guy gets close to you, he STEALS whichever weapon you happen to have out at the time. NOT cool, especially after you've visited the Pack-A-Punch machine. Avoid him if you can, or keep your crappiest weapon out and hope for the best. Also good to know: the elevators stop working when the scientist comes out to play, so don't bother trying to escape to another floor.
Upgrade Your Weapons
Much like Kino, a convoluted path must be taken in order to reach the Holy Grail that is the Pack-A-Punch machine. From the starting area, make your way into the hallway and take the elevator down to the War Room, noting the DEFCON switches scattered around the walls. Take the stairs down (paying to clear debris as you go) and make your way to the freight elevator. Take THAT down to the laboratories and locate the power switch, just like Kino. Once you've got the juice on, head back to the war room and hit any DEFCON switch you see with a green light next to it until you hit level 5. An alarm with sound at that point, a cue that ALL teleporters will now send you straight to the machine for a limited time.
Death In An Elevator
There's no single location in Five that is easily defended with a convenient choke point. What you DO have is an elevator, and the breathing room a ride up or down can provide as your reload and revive. Five features two elevators: the one connecting the starting area with the War Room and the larger freight elevator, which connects the War Room and the labs. The latter is the one you'll want to call home. You'll have two entry points to defend, since that elevators two sets of doors both open on each floor, one on a barrier and one on the floor itself. This is offset by the fact that you can buy the SPAS-12 shotgun in the War Room, found JUST outside the elevator. Easy, quick access to ammo and an up/down button you can press for a moment to breathe when the horde gets to be too much.
BIG thanks to my Xbox Live gaming buddies Inflakable, Sloppy Octopus and ESPECIALLY Karmas Remorse for helping me figure all of this out.