We booked the Galleria Borghese in advance as we realised that they only let people in at timed intervals. We opted for the 3-5 slot and getting there at 3 it was busy but bearable. Two hours was about right as by 5pm we had seen all we wanted to see.
There are some amazing works on display here in particular the Caravaggios were a must see for me. The spaces were very light and a perfect setting for the artwork. A very worthwhile experience! Also don't forgot to use your Roma Pass if you have one as we got money off here too.

If you're in Rome doing any sightseeing, this should be your second stop after the Colosseum. The paintings and sculptures here were amazing. Just know that you need to reserve ahead of time because they only allow a certain number of people in at a time. They have audio tours but we got a guided tour in English (I think only available during the first entrance time at 9am). Do yourself a favor and go there.

I was a bit disappointed by the Borghese Gallery, probably due to my own lack of knowlegde. I'm sure I was looking at some very famous scultures and paintings, but to my untrained eye it was mainly ordinary-looking scultpures and a load of old paintings. Nothing jumped out at me with a 'wow' factor, which I thought would have happened despite not knowing the details.

Downgraded from a neutral score because of the ritual to get in. Booked in advance, then you have to collect your tickets on the day more than 30 minutes before your 2 hour time slot, which means 2 visits here in one day (better ways to spend limited holiday time than collecting tickets).

On the 2 hour timeslots: 3 till 5 means you can arrive after 3pm (I thought you had to be there for 3), people are let inside in 30 minute intervals, and all out by 5pm. Once inside, I needed about 45 minutes to see everything. 360 people are admitted in each 2 hours slot, it would comfortably hold more than that so the cynic in me thinks they are creating a shortage to make it more well-known.

The Borghese Gallery is simply amazing. You have space (especially if you go round backwards - as everyone is let in together try turning away from the crowds) and the most stunning sculpture in Italy. The Bernini done when he was a child is incredible. The Vatican Museum is my next best museum but oh, the crowds. This is really special.

We actually would have liked longer and used the audio guide and guide book avidly. Even the 6 year old was riveted. I felt that we rushed the paintings and next time am going to book two separate visits so that we can start with the paintings the second time.

It is a bit of a trek off the main routes. Bus or taxi a good idea and be early. They let your booking go otherwise.

Just do not miss it. Pony ride in the gardens went down well afterwards too.