I've got the economy 9 gallon morebeer kettle (it comes up on the deal of the day every so often for $69) and it works fine. I boiled full batches on my gas kitchen stove. I'm sure the heavy duty kettle would boil full batches quicker because of better heat transfer. But I just leave my SS immersion chiller in the whole time for better heat exchange and it gets 7.5 gallons rolling just fine. In sum, I'm happy with my purchase. Try bargain fittings for the valves, etc, though, if you want to save a couple bucks and get really good service.