Touring the Vatican Museums

"Skip the line" means you skip the ticket line (not the security line) and YES you definitely want to do that. It's not so that there will be less people, it's so you will have less time waiting in lines.

I can't say if it's worth the extra money or not to have an early-morning access tour -- a lot will depend on when you're going, and you're personal preference. It's not to me, but YMMV.

We did the early morning Pristine Sistine, and from pictures I’ve seen of the chapel full....yes, it so very much worth it. It wasn’t shoulder to shoulder crowded, easy to walk around. We are doing it again in September with our boys.

If you want to see the Bramante Staircase make sure to book a tour that includes it.
The Vatican offers this as one of their Hidden Museums tours. Dark Rome also has a tour that includes it. The Pristine Sistine tour through Walks of Italy is a great tour but, it does not include the Bramante Staircase.
I would book the smallest tour I could afford. It’s much easier to move around with a smaller group. You will be using headsets so if the 20 person tour is cheaper, that will be fine.
Have a wonderful trip.

Here's the official Vatican site.

https://biglietteriamusei.vatican.va/musei/tickets/do

Skip the line and early entry are essential in my experience

I have the same question. I wonder how people feel about the difference between pre-opening entry and an 8:30 am booked slot. 8:30a.m. is probably the best I could do given I'm not a morning person, though, I have tentatively also booked a pre-opening entry

I have visited twice, both times without a tour. If you book in advance, there is a separate (shorter) security line, then you go to the ticket counter to pick up the tickets. Then you go up the escalator. At the top on the right is a gift shop (there are more along your route through the museums). The top of the Bramante staircase is behind/next to the shop. Before you enter the main museum, you can visit the Pinacoteca and the Pio-Christian museums. There is a one-way route through the other museums that takes you to the Sistine Chapel. Tour groups usually exit there for the shortcut to St Peter's. Sometimes guards let individuals exit there, but don't count on it. The rest of the route goes through a lot of relatively boring rooms to get back to the bottom of the Bramante staircase. I don't find the crowds in the Sistine Chapel to be a problem because they don't obscure the views.

I like to linger in museums so I don't take guided tours. There is an audio guide that I found to be very useful.

Hi! My friend and I did the skip the line AND I HIGHLY recommend a private tour guide found in RS. There will be vast amounts of people as the Vatican does not limit in any way the amount coming through the door.

I assumed the OP wanted to see the original Bramante Staircase which can only be seen on specialized tours. There are two Bramante staircases.
Perhaps the OP can clarify.