I've been up there before, but it's been a while. I didn't really have any issues at the time. I'm definitely not fast by any means and I'm not going to be breaking any records, I just want to finish it.
I'm in decent shape now after completing three marathons the last year, and I'm not sure how much longer I'm going to want to keep it up, so it may be now or never to do this. I've read about everything I can about it, so I understand the ridiculous task it's going to be. After my next marathon in January, I'm basically going to be doing stairs, hills and inclined treadmills until August in order to prepare.
It's kind of like a Forrest Gump thing to me. "I ran this far, might as well keep running." I ran up, might as well run back down.