I understand that there are accessories, but it seems like you could use any of them just sitting on tope of an ordinary grate (except maybe the wok). Even for the wok, you could pick up one of those steel collars that come with other woks, place that on the grate & your wok on that (although it would be farther away from the coals).
It doesn't seem like the center of the grate would really be saved very much. The wear from using the accessories on a regular grate would seem fairly minimal unless you are using them all the time & even then, not really a big deal.
The GBS just seems like an overpriced gadget that really doesn't seem to accomplish very much, if anything, to me.
I'm really curious to find out if people who use it find having an opening in the center is that big of a deal for anything they tend to use it for. To me, it just seems like a way to spend money just to make sure a cast iron griddle, or whatever, is perfectly centered.