I realize this post is old, but since then, my friends went on the Freedom and their sons used the FlowRider. They said the lines were long and it wasn't open all day, just certain hours like many of the other venues. They said they were able to stand up without a problem. Some chose to lay down on the boards (or couldn't get up), but they stood.
Looking forward to my DH & sons trying it. I wonder how close it is to real surfing?