My friends dad own a tower building business and one of my friends took a job there for the summer and said it was crazy. Literally everyday he was scared shitless. When he got the job he didnt know free climbing was a part of it, and since all the experianced workers did it, he had to also.
He never climb a tower that high, but i think he said he climbed ones close to a 1000 feet and it was crazy. the only reason they dont hook up every time is because it takes to long, and everyone is just really comfortable with climbing.