Yup, I know what a grille guard is. Just trying to keep you from spending money right after buying a new truck. They don't do anything to protect the vehicle, just look "good" (to some). The Shrockworks (or an ARB) bumper is steel, like 5/16" thick if I recall. It protects your vehicle a LOT more if that's what you want the grille guard for.
This is what happens if you get into an accident with one (and yes, it's a 2002-2004 Nissan Xterra, but the design is the same and I HIGHLY doubt they've started reinforcing them).
http://s242.photobucket.com/user/drb..._0354.jpg.html
I know the feeling too, I SWORE I wanted the grille guard for my 04 Xterra, almost pulled the trigger and then people started explaining the downsides of it and I decided against it. Also, if you plan on doing ANY offroading at all, the grille guard will reduce your approach angle, meaning you can't go over as big of obstacles even though the suspension could handle them.
eta: If you want sliders (step rails made of steel), look into the Shrockworks. They stick out beyond the doors and act as very nice door ding guards. I have come out of a store before and found people parked close to me and then noticed they slammed open their door and the lip was dented seriously. Only thing that happened to my sliders, was the paint was chipped off. I opted for the bare metal version and primed/painted them myself with rattle can texture that matched the factory grey quite well. Now they're mostly a rusty brown because the paint has chipped off in so many places from slinging rocks out of my tires![]()