Some are designed for that use. Setting the back burner of my Genesis
to its low setting 190F. I left it on for a weekend, still had gas
left, and the temp was 190 as it was 2 days earlier...
Had a Bandera, it was a mess. Very diff to clean, crudely made. Found
the weber smoker attachment about $70 to smoke just as good, get nice
smoke ring and I've smoked dozens of delicious brisket and some of the
best smoked trout I've tasted. I've been using a genesis for the last
14 yrs. It maintains a set temp very well. I use a DCS grill for
grilling. The weber for eveything else, including a 23 lb stuffed bird
last month.
I agree there are prob more efficient smokers. But put that weber
smoker access on a genesis, and it works great.