Stopped by TSC on my way home this evening and checked this cooker out.
Externally it looks to be about the same size as an 18" WSM. The door on the model I saw didn't look as if it sealed really well. Like the WSM, some gentle persuasion could move it back into a better fit. It has a thermometer in the front of the lid, just above grate level, but I imagine that it would read high, since there is no internal probe and it's reading the temp at the edge. The exhaust stack is bolted on and could allow for some air leakage, but not too much.
It is designed for the charcoal to go on top of a charcoal grate that sits in a pan. One of the grates is designed to set on top of this, making it pretty much unusable for cooking. The water pan is designed to set just below the top grate, but you could put that on the lower grate, but I am sure you would go through a lot of water that way. Input air control is controlled by a small air vent with three holes on the bottom section of the cooker.
One nice thing is that it does that two small bars in the lid that can be used to hang something in the cooking chamber. Of course they aren't really that strong, so you couldn't put much weight on them without bending or breaking them. You would probably have to remove these if you wanted to do Beer Can Chicken or a small Turkey, as they would probably get in the way.
All in all, considering the price of $69.00, this cooker does have some potential if you are willing to apply some mods.
As for the firebox, I would build a stand-alone firebox of expanded metal (similar to that of a UDS) and use the charcoal pan for something else. You could use the second grate to create a second shelf by lowering the hardware that holds the water pan and get some extra space.
I don't believe it to be as sealed as a 18" WSM, but the leaks are fixable, if you want to take the time. It's no WSM, but with some love and care it could produce some pretty decent Que. If I decide to get one, I will give you more of a write-up on how it functions.
