This tour is well worth taking up. There's so much to see and understand on this ancient site that makes it impossible to "go it alone". Our tour guide, who was an archaeologist, was knowledgeable and informative, and also spoke very good English. The tour lasted the best part of the morning so skipping the line makes the most of your time.
This tour is brilliant. The inside of the Basilica is really quite breathtaking, and was brought to life through our guide whowas very knowledgeable and spoke perfect English as well. But the tour also included information about St. Peter's Square explaining the connections with the Basilica to give people an all round understanding of the whole site. The queues waiting to get in were long, even in February, so skipping the line really does save time.