"A heavier model won't fall to the ground any faster." - Actually it will due to wind resistance, i.e. a heavier model has more force acting on it via gravity compared to the same model that weighs less. This allows it to overcome more wind resistance, hence a faster free fall.

Intersting note about cubic loading. This sort-of fudges in the scale factor/reynolds.

Ditto on you must compare similar planes to make much sense of the numbers. Giant scale aerobatic planes, i.e. 35%-50%, often have what seems to be a high wing loading, but they feel light in the air due to the higher renyolds number they operate at, i.e. the wing got bigger but the air denisty stayed the same, so the wing is more efficient.

-cheers