I have a Good-One Marshall barbecue smoker grill that I've been using for six months now. It's fairly easy to maintain burn and cooks evenly with nice consistent heat throughout the smoking chamber.
From my experience there's about a 35-40 deg. temperature discrepancy between the very top grate and the fourth lowest one. Another thing about these cookers is that they have a good temperature range easily manageable up to 400 or higher for searing and anything you wanted to cook at higher temps. It does not come with an adjustable charcoal pan or grill grate that you can adjust. I've made a few minor adjustments to mine in that regard and also had a charcoal basket made. You won't have to use a lot of wood with these to get the smoke flavor you want and they have good efficiency burning. Works much like a convection oven. Very good capacity. I do wish that at least these came with an insulated firebox. You can both barbecue and grill on a smaller scale with these units. Personally, I think that they are overpriced but I can't bark about the way this one performs for me.
Simple to run cooker and puts out some awfully nice BBQ.