This is one of the coolest things you can do. It's well worth the $200 for the experience of a life time. I've read 2 negative reviews and I know everyone's entitled to their opinion even if the opinion is ignorant and complete bs.
When you're up there you can see for kilometers. I went for my 30 birthday and the weather was perfect. You can lean out forward and backwards, you can walk the edge and on the last part you can just hang out and relax.
The platform is about the size of the a sidewalk and you're attached to 2 harnesses. From the ground floor to the too is very fast and leaves no time to back out.
For an added bonus when you're done go jump on the glass floor and watch everyone clear off like it's lava. ;)
Bottom line if you've got the guts go for it. Yeah it's $200 but an awesome memory and a crazy feeling can't have price put on them. (Unless you're a cynical a$$hole)