Yes commercial aviation tends to use the 3 deg approach method but you don't make wide turns when driving your car even though commercial (truckers) drivers do. Unless you trust your engine 100% dragging in a model airplane on a 3deg approach is a sure way to end up short of the runway with a dead stick. A model jet will fly a 3deg approach without a problem, however a trainer or scale bipe will require a lot of throttle at slow speed to maintain a 3 deg slope. Even small single engine F/S aircraft will fly a steeper approach when flown by the numbers. Find a good comfortable slow speed at which you can still easley control the plane, reduce throttle to give you a nice descent, without allowing the engine to load up, and fly that approach with that rate of descent. As long as you are not diving at the runway and can easily level off and flair don't worry about the angle.