I have a masterbuilt 40 Ive been using for about 3 or 4 years. Im not sure exactly which one you have, but below are a couple pics of the one I have. It puts out some pretty good food. The chip tray holds only a handful of chips that last me about an hour depending on what chips I'm using. Keep an eye out when you place food directly over the heat source because it will burn if you're not careful. Sometimes I use a sheet of foil on the rack over it to deflect it. Helps to rotate the food a bit, just keep an eye on the color. If you're cooker has a control panel that is removable and you leave the cooker outside, take it off and bring it inside. They can be sensitive to weather(had to replace mine). If I'm only doing a rack or two, I fill the water pan. If the racks are full I've found that the water isnt necessary but it doesnt hurt. Helps bring the temps back after you open it too. Keep the top vent at least halfway open or preferably all the way. Too much smoke and it will taste nasty. Keep the airflow moving. For most cooks, I will usually fill the chip tray about 3 times, sometimes 4 depending on the cook. You will have to experiment a bit to see what works best for you. Hope we are talking about the same cooker. Good luck and have fun with it!
Santa Maria 30x20