Stockholm vs Oslo

I really enjoyed both cities but think Stockholm merits more time.

I also loved both cities , having spent four days in Stockholm , and a week in Oslo . Oslo , however , had a distinct pull on me due to various experiences and reading over the years . Having long been interested in polar exploration , the museums on Bygdoy in Oslo ( particularly The Fram Museum ) were a must for me . This history of the 1910 South Pole expeditions is among the best books I have ever read - https://www.amazon.com/Last-Place-Earth-Amundsens-Exploration/dp/0375754741/ref=sr_1_1?ie=UTF8&qid=1525052997&sr=8-1&keywords=the+last+place+on+earth+scott+and+amundsen%27s+race+to+the+south+pole&dpID=51IZLYScVtL&preST=_SY291_BO1,204,203,200_QL40_&dpSrc=srch Here is the film based on this book - https://youtu.be/P8hB3TPEJcQ . If you love fine art . this gallery in Stockholm is well worth your time - https://www.google.com/maps/place/Thielska+galleriet/@59.3228773,18.1444786,17z/data=!3m1!4b1!4m5!3m4!1s0x465f829bdf7b27bf:0xc75afbfcb900fdbf!8m2!3d59.3228773!4d18.1466673

I have yet to visit Stockholm but agree with Steven about the Fram Museum.

http://frammuseum.no/

Not only was Fridtjof Nansen an early arctic explorer who was the first European to ski across Greenland and the scientific explorer who traveled the "farthest north", but also a Nobel Peace Prize recipient.

https://www.bivrost.com/the-crossing-of-greenland/

More than a century ago, the Norwegian Polar explorer Fridtjof Nansen
led a group of bold adventurers where, literally, no-one had gone
before: across the ice-sheet of Greenland.

https://www.youtube.com/watch?v=PkfNvFBwbnk

[True Story of Epic Adventure of Nansen] Farthest North, Volume 1,
Part 1 (Audiobook)

Nansen vividly describes the dangerous voyage to the North Pole by
sledge which lasted for 15 long months.

https://www.nobelprize.org/nobel_prizes/peace/laureates/1922/nansen-bio.html

Polar Explorer and High Commissioner for Refugees

In 1922, the Norwegian Fridtjof Nansen became the first High
Commissioner for Refugees appointed by the League of Nations. After
the First World War, he was in charge of the exchanges of 400,000
prisoners of war between Russia, Germany, and the former
Austria-Hungary. Nansen also engaged in humanitarian relief work in
1921, during the severe famine in the Soviet Union. His work on behalf
of prisoners of war and starving people earned him the Peace Prize.

Nansen was a scientist, polar hero, political activist and diplomat.
He got a PhD in zoology in 1888. In the same year, he was the first to
cross Greenland's inland ice. He subsequently failed to reach the
North Pole, but became internationally famous nevertheless. Nansen was
a nationalist activist when Norway broke out of its union with Sweden
in 1905.

Thanks for the info on the Fram Museum. Sounds great. We have added it to the list.

I much prefer Stockholm. Both cities have plenty to do, but Stockholm is far more beautiful.

We spent 5 days in each city and I'd be hard pressed to choose one over the other. Of course that's a matter of personal taste anyway. IMO, half a day is not enough time to be greatly concerned about. I'd list the sights I want to see in each town and allocate the extra 1/2 day to the town that contains the highest priorities. Enjoy your trip, both towns are wonderful.