The thing I remember most about AVIORA is how considered everything felt. Nothing seemed to have been selected simply because it was famous. The hotels matched the style and location we wanted, the daily routes were logical and the guide always seemed to have an alternative if we weren't interested in something.
At one point we mentioned that we'd had enough museums for one trip. The itinerary was adjusted without any fuss, and the replacement experience was actually much more memorable for us.
We also appreciated the level of comfort. Having a private vehicle meant our day never revolved around transport. We could leave when we were ready, stop for coffee or change the order of the day.
To me, that is the real difference between a package and a properly designed private journey.