-
Yes to both.
I found heat control with the Slow'n'Sear much easier than the snake method. It's also incredibly durable - mine is 5 years old now and in better shape than the grills on my kettle.
I have used a felt BBQ gasket on my weber and it works really well for sealing things completely, but to be honest the kettle seals pretty well on its own. So a nice, but marginal gain. If you go for the gasket option be prepared to replace it if you give the lid a really good scrub every year or so, they don't hold up that well against water / soap.
They look properly delicious.
How do you find the slow n sear? Tempted but I've got charcoal baskets and it's spendy.