We just returned from Norway last week. Short answer: we really enjoyed the Flam train and last half of the fjord cruise (1st half not as scenic)
The main point of our trip was to make an expedition cruise in Svalbard (HIGHLY recommend !) but we added a few days prior to ride the scenic Flambahn I’d read so much about and check out Oslo. Good thing we did cuz our flight from the US got cancelled and we were rebooked for the next night.
Our original itinerary was Icelandair US-KEF-BGO with overnight in Bergen and Aurland (ferry stop or short bus ride from Flam) with planned hike on Stegastein.
Due to canceled flight, we had a major regrouping starting with the flight the airline changed to US-KEF-OSL (missed 1 hr connection) -BGO using SAS (before strike( for last leg
Luckily I was able to move my overnight in Bergen to the next night for an additional cost, but would not recommend that hotel dye to these issues experienced with them.
I had to repurchase the fast ferry (norled) from Bergen to Flam (~5hr) and loose the money on the Aurland accommodations,
We were able to recover and adhere to original plan once we got on the FlamBahn to Myrdal, transfer to VY train to Oslo.
Was the cruise to Flam and train ride worth the aggrieved it turned into because of the flight changes? YES!!!
If we didn’t have to make the plane to Svalbard I might have reworked the whole itinerary to keep the overnight near Flam, but might not have been possible cuz there’s not a lot of places to sleep and those available last minute are expensive or very basic hostel situations.
By the time we got to Oslo at 2045, we were tired from traveling 4 long days in a row. The planned earlier arrival to Bergen and overnight near Flam we’re sorely missed!
do the trip to Flam, either via NIN or fast ferry, ride the Flambahn. If it makes more sense for your overall itinerary, I don’t think you’ll loose much by doing a circle from Bergen instead of going one way between Bergen & Oslo.