A bit like Alaska. A verandah will enhance your experience once you are inside the fjords, but there are several mitigating factors.
1. One of our favorite parts of an Alaskan cruise is sailing the Inside Passage, but the route to and from the Norwegian fjords is in the open sea. There's nothing more to see there than on any other day at sea.
2. The ship docks inside the fjords - unlike the sail-by near the Alaskan glaciers. You can head to the top deck, into the port, and up the surrounding mountains to get amazing views all day long.
3. The weather is much warmer in the fjords than near the glaciers, so you can spend quite a bit of time on the top deck.
4. The fjords are narrow, and the surrounding mountains tall. You won't get it all in one frame if you are in your verandah. In particular, the views from the deck 8 verandahs will be more limited due to the overhangs.
5. Disney likes to call any itinerary visiting Norway the fjords itinerary. Unless the ship is visiting a port actually inside a fjord (such as Geiranger or Olden or Flam), you will mostly get to see just the North Sea from your verandah.
We were on Magic last summer (2019) and loved our verandah on the days the ship visited Geiranger and Olden. We didn't use it much - if at all - on other days.