While that's true, it's also true that it's worth trying different brand props in the same sizes to see what works best with your engine/airframe combination.

In may parts of the US, APC and MAS are the two most common props. And in most of the common sizes for sport planes, the APC props tend to have a bit more pitch than MAS props. For example, a MAS 10x7 will sometimes perform simular to an APC 10x6.

Also, in many sizes, the APC prop design is a bit more efficient and the blades are stiffer, which sometimes you can notice in the air, and sometimes you can't. Depends on your exact situation.