I have this unit as well...it is my 2nd smoker - the first one being a CharBroil unit that had no thermostat to keep the temps consistent.
While it's not "insulated" like you may think, it is double-walled (a silver interior attached to the black exterior), so it holds heat pretty well. No door insulation to force smoke out of the vent in the back...but it still smokes pretty good.
I'm not sure why the one poster said he needed to refill the wood every hour...I can run ribs (3-2-1 method) and I don't need to add wood. The wood chip dish has a lid that is designed to keep the chips from burning instead of smoking...I know some people over-fill the chip dish so the lid won't fully close and that lets in air that helps burn the chips...so maybe he slightly overfilled the dish? I know this unit practically sips wood as compared to my CharBroil that would suck up an entire bag just doing one day of ribs - this one uses about 1/3rd of the wood.
The thing the other poster talked about - holding the knob down...that is SUPPOSED to only be needed when you first light it...I think it kind of overrides the valve setting to put full flame out of the burners and warm the system up to sense the flame. This unit automatically turns off the gas if it flames out...I THINK that's what you are warming up by holding the knob down...but that usually only takes maybe 30-45 seconds to do.
I find that using a digital thermometer, the unit runs about 25-50 degrees colder than the knob (at least mine does)...yours may vary.
Personally even though it's small, I love this little unit. Yes, you have to cut your rib racks in half, but if you get two of the vertical holders, you can do about 5 racks at a time in this unit.