IMO Zion NP is one of the most beautiful and picturesque places in the US.
It's interesting. I agree somewhat but IMHO it differs from other known parks in a certain sense.
A. Unlike famous attractions e.g. the Grand Canyon or Bryce Canyon that no matter which viewpoint you go to, you'll be awed (perhaps some points are better than others, or better sunrise/sunset etc., but even at the worst viewpoints, you're still wowed to some extent -if you haven't yet been exposed to the better lookouts). You can drive in for an hour, never have looked at any guidebook or map, or gotten any tips from anyone, go to a lookout and just be blown away.
Zion is different. There's no one central attraction (technically the valley is). You can go spend a few hours in the park and come out saying it was lame. Unlike the aforementioned NP's, by Zion it's really about knowing beforehand where to go. Even asking rangers you'll get so many different opinions what you should see (IME).
B. Another difference is, to really see Zion you
must hike. It doesn't have to be one as scary as Angel's Landing, but without hiking even a short hike to see the valley, don't bother going to the park IMHO. And I say this as someone who avoids hikes at every possibility (blame it on the kids).
But like I said above, key is to know
which hikes to go on, as some may be really not that exciting.
C. Roads outside the park are nicer than what you may see inside the park (if you don't hike). The road leading to the park is incredibly gorgeous.