Well, one pretty obvious advantage of pp2s is that they sit in the library and you can just click on them without having to go look for an obj and import it. A flowerpot doesn't need to be a pp2, but it won't take up much more space as a pp2 than an obj. And, as I said, you don't need to hunt for it. Other than that, smart-propping and morphing are the obvious advantages. Texturing is no problem, nor is scaling. Although, when your prop is smart, you can apply MATs to it, which makes texturing easier. All in all, I'd say pp2s win over objs mac