Ha, I just clicked on this post to answer it and realized it was my post from 2 years ago!! It must be Kent’s great instructions on how to find old posts that had it come up again. It’s also a reality check that I have been using this site near daily for about 3 years..
I ended up taking some advice from you guys and booked with Rome Walks for the Colloseum, and Through Eternity for the Vatican. I really enjoyed both of the tours. My Through Eternity tour guide was an art history professor from the US just giving tours for the summer, so that was extra special.
Part of my motivation for doing a tour was that I was traveling by myself, but I found that I learned so much from the tours that I would have just missed had I done it alone. This summer when I go to Greece with my boyfriend, we will use a tour for the Acropolis because of my positive experiences with these groups. Thanks again everyone =)