I know this is a tender subject for some, so I won't delve too deeply...but to me, the GrillGrates are the Great Equalizer here. The "flavorizing" surface is right below the cooking surface so the effect is intensified, the searing capabilities are well beyond what I would ever need, and any flareups are kept well away from the cooking surface.
All I am saying is that the gain to be had is not worth the effort it will take to install a 13-bar cookbox in a 5-bar frame, from what I could see from my own limited view. I would love to do it, but what is the outcome? A Frankengrill. I completely understand Bruce's desire for a bullet-proof SS frame for his 13-bar now, and that has broadened my view. My motivation was to have a 13-bar in a Silver frame because the thermoset tables are much more practical and I love the enclosed cabinet in my Silver, hardly a strong enough motivation to do the modifications necessary. I think Bruce's motivation, having a rust-resistant grill in a more extreme environment, is much more of an imperative than a whim for thermoset tables and enclosed cabinetry.
Without question, the Genesis series is by leaps and bounds, far and away, the most beautiful. The Silver is the more practical. I have both and I am happy. I can't bring myself to try to have the best of both worlds in one grill.
I roti'ed a rib roast on the BGE this weekend. You want to talk about a long cool down? From 400F to ambient, about 10-12 hrs. with no air leaks. I use a HeaterMeter (shoutout to Bryan!) for precise temp control, and I really, really hate to say this, but we are getting used to the "clean" taste of a gasser after 30+ years of coal burners.