Welcome to the Newschoolers forums! You may read the forums as a guest, however you must be a registered member to post. Register to become a member today!
As a park ski, I would have to say the thalls are better. They both shred the park, but the thall is more flexible, so butters will be easier, and I think they will be a slightly better rail ski that will give you better nose and tail presses. The biggest thing about the thall I think is that even though its super buttery, fun and light, it can handle big jumps, and you could even have some fun in the pipe with it. For both, the durability is exceptional.
That being said, the thall is pretty much a park specific ski. Yes, you could play around on some groomers, but the AR7 will give you the higher performance that you may want outside the park. Hope this helped.