Aluminum spinners are usually used on bigger, fancier planes for looks while the plane sits in the pits. For trainers or most planes I wouldn't bother. They are expensive and as you found out may not be as user friendly. Personally I would just stick with nylon spinners. They should be less of a problem and also offer better protectiion for the engine in case of a crash by absorbing some of the impact. As far as wooden props goes, I tried em and don't use them. If the engine is running and the prop touches anything, even slightly the prop will instantly break with a loud snap! Master Airscrew are great for training because they can take a divet out of a grass runway usually without damage. For higher efficiency props use APC brand. Not quite as forgiving if the prop contacts something but the prop produces more pull for the same engine. These other props are also a little heavier than wood props which acts as a fly wheel. This allows a better idle at lower speeds. [8D]