I agree with Tony, I spent three years buying, trading, and modding cookers in a quest for Temp control and realized that for a back yard cook its completely unnecessary. I have an ATC and it does a decent job but i can cook fine without it. Use your best judgement to control how much lit coal you start with and let it go. As long as you are "within range" of your target your food will be fine. If cooker runs hot it'll cook faster, if is cooler, it'll take longer.
Once i embraced the mantra "let the cooker cook", i enjoyed BBQ more because i stopped worrying about it.
