I didn't touch the create a park until downloading it so I don't even know what's different. Feels like I gave them 6 bucks for nothing.
The only things that are new are the items that start with "DLC," most of which are useless garbage in the "other props" section, and the "Misc. terrain" section. There are literally less than 5 items which are useful, and even then they can mostly be made with other stuff that's already available (bent pole, are you serious?).
Now you can skate as Slappy and Fabio (RIP).
They also updated the replay editor, but anybody who's actually interested in editing enough to use this would already be using an editing program with capabilities that are 100x better. It's a fairly useless tool that sounds way better than it is.
My biggest letdown was no (worthwhile) new clothes, when they were talking like there would be some good stuff. Who the fuck cares about a beanie with a ball on top if I still look like a cancer patient?