Here's a taste:
MRAP is an unusual program that involves rolling purchases of a wide range of vehicle types, all meeting the same basic mobility and protection requirements.
The requirements do not specify how a vehicle should meet them, so manufacturers take different approaches, with some embracing a monocoque style that combines the hull and chassis in a single piece, and others bolting an armored hull to a separate chassis, perhaps with a "belly plate" to protect the drive train. All hull designs are V-shaped, though some are flatter than others to maximize interior space.
Note above that the story says all MRAP hulls feature a V-shaped design, contradicting a report I posted weeks ago about the MaxxPro vehicle. Based on the comments I quoted back then, I don't necessarily buy this part of the story. I wouldn't be surprised if the issue boiled down to semantics in the end.