I have an Oklahoma Joe Highland Offset smoker and I love it! I debated getting the reverse flow version, but I'm happy with this one. I smoked a brisket for 12 hours a couple weeks ago and it turned out great!
Recently picked up a masterbuilt 1050 new in box from a local auction site for about half price. Prior to that I was using a chargriller offset barrel grill/smoker that I had added a ton of lava lock gasket to in order to make it somewhat smoke tight. I decided I'm getting too damned old to have to get up every two hours to tend to a smoke box just so I can have brisket.
My 560 kept having massive flare ups after two years of ownership no matter how I cleaned it. You got a great deal but it is not going to last long IMO.
I had the 22” when I lived in Texas, moved to New York for a while and gave to a friend. He got me the 18” once I had a yard again since the shipping would cost so much. It was nice for the rare occasion that I wanted to cook a full rack of ribs or like multiple turkeys. For a single butt or brisket though it used so much coal even with the ring method. No upgraded door, I just buy a bunch of ends and pieces, put em in my cast iron, crank the vents all the way open and coat the inside with fresh grease while I’m seasoning my pan.