The problem with the Coastal Express is that what it passes northbound by day it passes southbound by night, and vv so to get the best out of it you really need to be on for the round trip/and or be using it as a ferry, hopping on and off because port times are far too short. They are for passenger turn rounds and freight only, not sightseeing.
Some of the excursions take you port to port to try to make up for the lack of time, at a price.
For instance you really should visit Tromso, but you have 4 hours there northbound in the afternoon, and 2 hours southbound at midnight. 4 hours is tragically short to do justice to Tromso. A full day on a normal cruise is pushing it.
Trondheim, Norway's original capital is a bare minimum 2 days to me, but you have 3 hours in each direction.
For the North Cape from Honningsvag that only works northbound- a 4 hour call which is just time for the bus to the North Cape, a fairly short time there, and the bus back. No time for anything else- a cruise call again works way better.
To see the Lofoten Islands the timings south are definitely better.
For me Kristiansund is a port not to be missed for the Atlantic road, the Marble Mines and more, but it is a late afternoon 1 hour call south, 15 minutes at 3am north. Again a full day cruise call works way better.
Some of the better ports to me are ones the Coastal Express doesn't even serve- Andalsnes, Alta and Narvik, South of Bergen the ports of Stavanger, Kristiansand and Haugesund are good ports not on the route.
On balance the northbound voyage is probably best if that is all the time you will ever have.
You will see lots of great Norwegian scenery, but nothing much of the ports. By the end of it you will certainly be planning a return trip at a more leisurely place. Any which way you will have a great time.