I will agree that the suburban doesn't have the greatest 4x4ing attributes but mine has probably done a help of a lot more than 50% of 4x4s on the road. Besides its more fun when its a challenge.
Don't get me wrong mate, I would love to own one, and I am not dissing your ride. On the street, you would feel like a king.
On any reasonably flat place, through water, light mud etc, no dramas at all. But when it comes to serious offroading, in their standard form they are inferior. Tough and powerful, yes, but not as good as most of the rest of the pack when it comes to actually going somewhere seriously offroad. They are too heavy and sink like a stone in mud or deep sand. They cant cross narrow gullys and creeks, and have absolutely no chance of doing stuff like ari's photo. That car has had an absolute fortune spent on it, and now it can crawl rocks. It will be an absolute pig at doing anything else though, its been purpose built.
I mostly use to run street treads on my cruiser (tread patterns, not tyres). They were better in sand, tracked straighter and quieter on a corrugated dirt highway, and were more comfortable. For the small percentage of times when I would NEED to travel across a black soil plain or serious rocks, it just wasn't worth putting up with Gumbo Wide Mudders. That's what winches are for. That and snow chains, which I carried a set of (some strange looks from people when you live in the top end, but soooo useful on the black soil).
The operative word there is NEED. If you live in the bush, rather than just go out and see how many times you can get bogged on a weekend, you avoid bogs if you can. You just want to get where you want to go. Getting bogged is only fun if that's what you are trying to do.
