I have not tried Sky High yet, but from the pictures it appears very similar to me. I am supposed to be getting a sample of Sky High sometime in the next week or two, and once I try it I can do a little comparison.
I was concerned that Souten wouldn't give me as much sheen as I wanted, but it has far exceeded and surpassed my hopes in its glorious pinkish purple sheen!
One thing to note, is that sheen doesn't show up on many papers. You need a special paper like Tomoe River, or Onion Skin paper to be able to really see a lot of sheen. (At least in my experience and from what I have read.) Clairefontaine and Rhodia will give me some sheen, but nothing like Tomoe River.