It can be confusing installing content at first, you need to get to know the runtime structure and then it soon becomes second nature as to which files to put where and which can be moved to make products easy to find.

I don't think you can say which software is better, it is a bit horses for courses. Some people find Daz Studio a breeze and some the same for Poser. It just takes time to learn your way around whichever software you choose and ask if your stuck. Plenty of help around on the forums if you need it.

I use Daz Studio myself, but lots of poser scenes and prop content. Just takes tweaking of the surfaces and they work fine. I would imagine it works the same in reverse. Persevere it just takes a bit of time.