gillmacca said:
How much smoke does it produce, and is there a base on it (to keep the fire off the ground)?
Martyn is quite right that this item has been discussed quite a bit, but to answer your specific questions:
The amount of smoke depends, as with almost any "real" fire, on the type of fuel, its dampness and the amount of ventilation it gets. Generally the fire in these small cookers is small, and ventilation is adequate enough to keep the smoke down if you use fairly dry fuel. Personally I find it easier to light the fire outside of the cooker and then drop it in, but this could be my poor technique as much as any quirk of the stove.
There is an integral base which folds down when you open the cooker. It raises the fire a short way off the ground, but it is full of holes and so you should certainly not trust that it will protect the ground beneath it. Never light one of these things over anything that could catch fire. The hinge mechanism is fairly ropey, by the way, but robust enough if you take care when opening and closing it.
