Thanks for sharing your pics, Jim!! Glad you're enjoying it!
Bob's been working on this design for ages trying to get it dialed in just right. Previous designs just weren't holding the temperature consistency edge to edge to MAK Standards, so Bob has been tweaking the design for a number of years to get this dialed in perfectly.
The biggest change (as you can see from Dave's pics that Jim shared) is the funnel design under the pans, which directs the heat up towards the cooking surface, so the heat gets where you want it (instead of heating the entire belly of the grill). We still govern the grills out at 500° to minimize grease flare ups, but with the heat directed right to the grates, the grate surface is much hotter than the overall grill temp when the FZ covers are removed.
The temperature also recovers more quickly when you open the lid.
We also increased the pitch of the grease tray to help with grease runoff. And instead of having the covers be left and right, the new system is split front to back instead (and the cooking grates split that way as well).
The firepot is still removable too, and you only have to take out the FZ pan to remove it, not the whole funnel system. Which is good, because all in all, it's about 35 lbs of stainless steel!