Luckily to me, I had a chance to go up to the Sky Tree few days ago. It was soooooo wonderful!! Magnificent! Actually, I live in the 21st floor in my apartment and work in the 31st floor in my office and I am very used to the sky view of Tokyo...but, the view from the Sky Tree was very different from the ordinary ones. I had a grand view of Tokyo until the horizon.
There is a "see-through" glass we can see from the observatory to the ground. It was so scared!! (I couldn't stand on it.) But don't worry, security is very much ensured. You know, the Tree was not affected at all even by the massive earthquake hit Japan in March 2011. This tower is located in the congested residence district of old downtown, but no accident was happened during the construction.
Tokyo Sky Tree(東京スカイツリー) http://www.tokyo-skytree.jp/