Full day at Vatican and Scavi tour- worth doing it?

It is very easy to spend a Full day at the Vatican. Besides what you write, don’t forget to climb the dome. Just an FYI, the first part is by elevator. On the roof of the Basilica is a lovely cafe, amazing views, a great shop - nice gold pieces, and bathrooms. So, if anyone wants to climb the rest of the way, the others have plenty to keep them busy while waiting.

And the Scavi Tour is definately worth your time. We were 3 couples who took the tour in 2017 and still talk about it.

Thanks for mentioning the cafe! We are wondering how to get food during this busy day?
When we looked for tickets at the Vatican we saw you can prepay for a meal inside the Vatican?
Anyone know how this works? Is there a choice of what you eat?

Yes, I think the Scavi tour is well worth it. From a historical perspective it is interesting, the location is a neat factor (that huge basilica on top of you), and depending on your beliefs, the connection to St. Peter can be moving.

The Vatican has opened another excavation, the Via Triumphalis Necropolis, it is available as a guided tour, but through the Vatican Museum (As opposed to the excavations office). It is located not under St. Peters, but under a car park nearby.

An added benefit of taking the Scavi tour is that you get to skip the line into the basilica. If you don’t take the tour, you would have to wait in the security line before entering.

The Scavi tour should be a top priority. It was 12 years ago for me, and I still remember the overwhelming sense of the divine I felt at the end when we got to peer through the crack in the wall to glimpse St. Peter's tomb. At another point, there's a grate in the ceiling you can look through to see Bernini's baldachin and Michelangelo's aligned directly over the tomb. Nothing on earth compares.

The OPs trip was last month but worth noting as this thread has been resurrected...
Helpful poster, Joby, provided the heads up that tours of the scavi have been cancelled between 19 August 2024 to 3 November 2024.

https://community.ricksteves.com/travel-forum/italy/scavi-cancellation

The baldachin is also undergoing restoration (expected completion by end of Dec. 2024) and Michelangelo's Pieta has been temporarily removed for replacement work of the protective glass (expected completion end of Sept. 2024).

https://www.basilicasanpietro.va/en/news/2024/renewal-works-of-the-protective-glass-of-michelangelo-s-pieta.html
https://www.basilicasanpietro.va/en/news/press-area/11th-january-2024-press-kit-restoration-of-st-peter-s-baldachin.html

But there are plenty of other reasons to visit the basilica during all the pre- 2025 Jubilee sprucing up!

We did Walks of Italy Vatican tour early in the morning, and then Scavi tour in the afternoon. It is doable, and Scavi was a highlight of the whole trip.