Oslo in Airbnb in August - where?
 

I'm usually good at this sort of thing, but am overwhelmed by the apartment options in Oslo. We'll be arriving by air and spending three nights before a cruise. Essentially I want something where we can walk to fun areas for dinner walking about and general tourist things. I'm thinking somewhere sort of west of the train station would be best??

West of the train station is the nicer part of the city, but all of downtown Oslo is quite safe.

With regards to walking distance St. Hanshaugen is good, and Grunerløkka is also quite good. Gamlebyen and Grønland is even closer to the train station and is interresting areas as well, but may not be your typical tourist area. Frogner, Bislett and Majorstuen are all very nice areas, but at a distance from Oslo S, and a bit to posh for my liking.

What are your options?

Many thanks, I was one the right track with St. Hanshaugen and Grunerløkka.

One unit we love the look of that's a bit out of the target area is closer to the waterfront:

https://www.airbnb.com/rooms/1593163

That unit is great for walking, and the building was completely renovated a few years ago (as you can see in the pictures). One small issue is the construction in Bjørvika but that shouldn't really bother you that much. Parts of the area west of lower Karl Johan has at times had a problem with street prostitution, not sure how it's now, but it never was a safety (more that a two-three blocks are not pleasant to walk through at night/late evenings.)