I'm just starting the Beast, meaning I've just got the primer paint on the unassembled parts. The problem is that I'm also building two other projects right now (a starship from Star Trek, and Green Lantern--both are almost done), so the Beast still has quite a ways to go.
But the model shows no defensive grid on the engine section whatsoever. The same for the Galactica, as well. The engine section appears to be the weak spot of these monsters, but I'd imagine it would still be a super bitch just to reach this area without taking a lot of flak from either the Bucket or the Beast (as well as their respective Viper squadrons).
And thanks! I'm debating right now whether I want to build it as the Peggy, or maybe as another ship in the Mercury-Class.