The huge front with the smallest windshield possible. Some enemy troops have been known to break and run at the mere sight of a grizzly, even an unarmed one.
There's only one way in. This could be a liability in case the vehicle get's damaged but it also defends against hijackers. Also, anything large enough to damage the Grizzly would most likely also completely obliterate it.
This is me trying to get a picture of the com center in the back. If you look closely you can see it.
And the comfy seats. There's room for about 6 guys.