My Weber warranty experience was grate, they replaced the Summit grates after year 2 or 3 when a weld or two failed, replaced the stainless steel hood when the regular steel inside liner rusted out at year 5 or 6, replaced the gas regulator when it cracked and replaced the flavorizer bars when they rusted through. Now all of the above occurred several years ago so it what it is, I also recall grates having a 3 or 5 year warranty.
The SS hood they gave me just a tad of push back as the SS was in good condition but the liner wasn't, I made mention of the rust falling on the food as it cooked and that's all it took, new hood on the way.