My husband and I signed up for the rooftop tour, but I chickened out and had to go back down after the choir loft part where we got to see the parade "giants". I have a terrible fear of heights and edges. He said it was a wonderful tour and he took many photos. It was an English speaking tour last summer. The tour leader said she did the English tour twice daily at that point.
If you find yourself in Santiago again, don't chicken out but go for it. It really isn't as scary as you might imagine. As I wrote above, I hate heights (couldn't do the Sagrada Familia in barcelona, crawled round Sacre Coeur in Paris on my hands and knees) and get horrible vertigo, particularly when looking UP, that totally does for me even on the first floor of anywhere! But I did the rooftop tour, and as I wrote above, it's actually OK. At one point I held someone's hand, at another I sat down and bottom-shuffled down a short slope, but it was OK. I loved seeing the city landmarks around me, the carvings on the towers and roofs. I didn't look up too much, and if I did I then sat down to stabilise myself.
Now, I told myself that it was part of my Camino, and something that as part of my Camino I had to do, like crossing the Pyrenees, eating pintxos in Pamplona, walking the Meseta at dawn, negotiating that awful descent into Molinaseca, climbing O Cebreiro, drinking that one-too-many glass of wine at dinner, going to Mass and seeing the Botafumeiro swing. Going to Fisterra and Muxia. Just something that I had to do to complete it, and I think for me that made all the difference to my attitude.
When I was up there and feeling wobbly, I thought, if this was in the guidebook as part of stage of the Camino, something we had to do to get from one place to another, we'd all do it without questioning it. So why not?
And you'll feel fantastic afterwards for challenging yourself and succeeding!