I have found that smoking the fish is much easier than smoking meat. If I was going to smoke a pork loin with this type of smoker, I would use less wood and more charcoal. That way the smoker will run hotter. This means the smoker would mostly have red hot coals and not make much smoke. This is different than smoking fish with wood only, you dont see many red hot coals(when opening the door). Also the water pan is filled with wood chips and water. But for beef im not sure if it matters much, since this adds strong smoke flavor. You could just fill the water pan with water-only, and stoke the fire with charcoal in place of the wood chunks. Get the thing cooked fully, then experiment with smoke flavoring techniques. It will still come out nice and tender no matter how hot the coals are, if you keep water in the pan.
I have found that when I use the smoke-fish stratagy, lots of wood chips in the water-pan, and stoking with un-burned wood, the beef comes out raw and too smokey. After 5 hours, its still to raw. But strips of steak cut like bacon will turn to beef-jerky in about 6.5 hours running the smoker this way.
I always start my smoker with charcoal that's red hot, just dump it in the smoker from the top with water pan out. Then place the water pan. For doing a pork loin id use charcoal briquets or charcoal chunks from wood or some-such to stoke the smoker. If you use un-burned wood chunks it will smoke heavy the whole time, and run much cooler. But you may want to use some wood to stoke with, when finishing up. That should add plenty of smoke flavor.
Keep the top sealed good, by placing the tinfoil around the top, you can still pull the lid and check things out easy enough. This keeps both heat and smoke in the smoker, where your cooking things. If theres a leak near the grates(around the top) where the meat is, things will dry out. You should have pitch-black water dripping from the bottom when your smoking heavy. This is condensate from the water pan dripping down the inside of the smoker. stoking with charcoal you will probably see this as well.
JW