I I like trimming mine to fly straight and level at full throttle. Like David said, all planes will want to climb with more airspeed. Some worse than others. I like a little down attitude on landing. Trimming the elevator down on full throttle Helps keep the nose down on landing and you don't have to worry as much trying to keep the nose from pitching up on its own. Just my personal preference. Everyone has their own. Shims would do the same thing I guess but you loose some of your trim authority.