I can sure see the advantages of stainless, but I guess that design doesn't really appeal to me. Too much flat area your food is directly laying on - almost like a griddle.
I am a cast iron fan, but agree that the some Q grates don't hold up as well. I don't know if it is another product that has gone downhill, but I can say that the grates on my 11 year old CharQ look almost perfect, and the ones that came with my first rather old Q200 were also amazing. On some of the new Qs it seems the coating is almost like thick paint that has dried but not really adhered - just begging to chip off. Maybe that isn't fair, but it just looks that way. I am avoiding hard brushes as much as possible and trying to use replaceable (or Dollar store throwaway) soft type scrubber pads on my current Q to extend the life of the grates.