This review is mainly about river boat cabins, and how size is far from everything. That will be in the cabin review section below. In short, the bulk of cabins on the Scenic Sapphire, and most if not all Scenic river boats, are classified as Balcony Suites. They are cramped and not very well-designed.
Most other things about the cruise were very good. In particular the shore excursions provided an excellent choice and the guides were good. (Not so the earpieces, which often caused problems, with a couple of guides abandoning them altogether.) Departures on shore excursions were not well-organised. The cruise director, who was very good, was generally ashore getting buses and guides organised. There were no staff with sufficient authority to herd the cats on board, with the result that passengers milled about pointlessly in the foyer. This led to pathetic cries from staff: "The captain will kill me."
With the odd exception, food was very good. Service in the dining room was good, with waiters trained in a fixed routine, at least for dinner.
On the Scenic Sapphire, Balcony Suites make up around 80% of the total number of cabins. They are all almost identical, advertised as 19 square metres (205 square feet) including the "sun lounge", which is the balcony. It has moveable glass that can be raised to close it off from the outside (but not entirely from neighbouring balconies).
Inside there is a single very small chair/stool which is at the desk at the foot of the bed. If anyone is sitting on it, the passage from the door and the closet to the bathroom, the other side of the bed and the balcony is impeded. Consequently, the only place a couple can eat and drink while seated in chairs is on the balcony.
The problem is that the balcony is not always useable. On any river boat, there are times when the baot is moored against another boat. If you were on your balcony, you could shake hands with the people in the next boat. There is zero privacy. This is unavoidable.
There is a better way of doing things, however. With a French balcony, the balcony is effectively part of the cabin. You have the use of the whole area in all circumstances. In particular, you have two chairs in the cabin, useable at all times. You just might need to keep your curtains closed.