I love my 680, but one thing I have had "issue" with was how long it takes to get toe max temp. 90% of my cooking is hot/fast, so I was looking at getting a mini then the discontinued.
This new setup has me really intrigued. I am hoping we get some vids soon showing how it does for sear marks and/or they will have grill grates for it.
Round has been the go to for grilling for ages, as mentioned, think Weber kettle, probably the most iconic grill around here in the US, and for simple reason they work. I am betting as mentioned it has to do with the round shape and good heat distribution. This to me combined with Lumberjack Charhickory pellets could be a real winner.