Sounds like you have the same smoker I do if it is the small 244sq. in. model. I love this smoker. Regarding temps, you have to check it pretty often to maintain temps within your desired range. This means opening and closing the dampers on the firebox and the smoke stack little by little to get your temp. The Minion method works really well for burning your coals. (Info is part of the e-course).
Also, you have to make the mods to the unit to really improve your chances of a good smoke: I think the most important are: 1) shielding the opening of the firebox, 2) extending the smokestack down into the smoke chamber, and 3) removing and stomping on the thermometer that came with your smoker. (The mods instructions didn't exactly say to stomp on that thermometer, but you get the idea).
The mods can be found here in the forum.
Here's what I have done: I have bought 2 10"x10" galvanized shingles from Home Depot and sandwiched a piece of fireproof gasket material between them (bought from Napa Auto Parts) to shield the firebox. I put a curve in them and screwed them to the same holes across the top of where the firebox attaches to the smoke chamber.
I have used aluminum sheeting, also from HD in the roofing department right next to the galvanized shingles, to extend the smokestack downwards.
And I've gotten a probe thermometer from Target to measure the temp of the cooking chamber. (Drill a hole in a piece of wood that the thermometer probe can fit loosely in).
I put a chunk of soaked wood right on top of the coals about once an hour to maintain a thin smoke.
With these mods I can maintain a temp around 200' for hours.
I've had this type of smoker, only the larger version and I find this small one works just as well and suits my smaller brood now that kids have moved out and I've downsized to a townhouse.
The only drawback to a townhouse is the neighbors are so close I always have to give them some bbq to make up for all the smoke I make. Small sacrifice though.
Good luck!