Our school never offered World, nor did i choose to self study it
but from my experiences in Euro and APUSH and the AP tests i would have to say APUSH is easier simply because a lot of it you have already learned or at least heard of. With Euro there is a broader timeline and some of the things taught you probably never hear mentioned. Frankly APUSH is more specific and detailed, Euro not as much but larger span of time and area.</p>