My Summit S670 has had no action since buying my E6 charcoal grill.
I love gas for its ease of use and ability to cook a massive amount of food, quickly and easily.
Personally, lump coal on the E6 tastes superior to anything coming off the gasser. And the additional 10 mins to get the coal grill ready for cook is a no brainer as I'll choose flavor over speed just about every time.
A gasser takes 10 mins to heat up to cook temp. The E6 takes 10 mins for the coals to become white hot and then 10 mins more once i place the grilling rack atop the coals for the grates to heat up.
So for 10 more minutes, food just tastes better.
I still like my gasser but am considering selling it this spring/summer. When I build my bbq island, hopefully this summer, i'll do a drop in gasser but smaller than my S670's size.
There's no real comparison on the food produced on a gasser versus coal. My tastebuds prefer lump coal over everything. I'll use briqs as a backup plan. But I do see the value of a gasser, but haven't taken the time to use it because lump is so easy to use these days.
YMMV. Do what's best for you and your family. There is no correct answer, I think....