Stick with it.I have the same rig and only modified last month after years of working/struggling with it. Should of found this site sooner
The mods are a great improvement, extend the smokestack to the grill, heat baffle and charcoal basket. I had already changed the therm and use a wireless digital therm for meat temps.
Done a test run two weeks ago with a new charcoal basket and had three hours of 230 - 250 temps with 5 lbs of royal oak lump. Outside temp was around 35f. Smoked some vidalia onions and made a batch of smoked onion sauce (still tweaking the recipe so will post it once i get it right).
I had the sfb vent about 1/4 way open and exhaust vent halfway open.
Going to try a boston butt and a fatty or two tomorrow. Local store is doing butts for $1.39 lb .
Hee hee i done my first fatty back in feb ....... YUMMMMM