After using one for almost a year (with propane/lava rocks. Never tried charcoal):
The cooking chamber/top part is made of low-grade material. Doesn't keep the heat out well and mine warped. Mentioned this in another post or two. The charcoal/lava rock pan is also not that great of quality. The jet burner, on the other hand, is not bad and the base is extremely solid.
When smoking, it can be a little difficult to keep the temps down low without modifications, but works fine for the most part. Easy to kick up the temps to 300 or so for chicken or what have you. To get to higher temps (such as for grilling), it takes a lot of propane for what it does, and takes a long time to heat up the lava rocks.
Because it uses propane heating lava rocks, there are more factors to consider. When you turn the propane up or down, it won't result in a direct temperature change. The rocks will take some time to cool down or heat up. If you turn the burner down, the temps often continue to rise. This can be a little challenging because you can't adjust the temperature quickly and have to take things a bit more slowly, like cooking with charcoal almost.
But overall, for $80 new (without propane tank), it was a good deal I think, and I still use the jet burner, which was about half the value of the thing. So really, it's like being out maybe $40 for me, which is the price of a normal charcoal ECB. Seems like a pretty good deal to me.