Our apartment has its own lockbox on the knob, which involved two difficulties for us (especially as elderly people). One was that the corner of that floor has no ambient light with which to see the numbers on the dials, so a good flashlight proved essential. The second was that it was confusing how to get the lockbox open once the code releases its latch- I tried a variety of strategies before it finally opened for me, but my wife spent some time on the same tasks that evening before giving up and calling me.
It is a charming apartment with hugely high ceilings- the kind of construction and layout which nobody would build today. Everything worked quite well so it is maintained nicely, and overall it is quiet, peaceful and well supplied with what guests should need. We saved a LOT of money by staying in this place instead of driving a car to there from a real hotel; the Link from SeaTac is $1 for old people with the discount ORCA card - you apply in advance via mail and it is completely free - but for anybody the fare is cheap and just a two-block walk to BOTH Pioneer Square stations).
The neighborhood is seedy with a tent city in the little park just across the street so perhaps avoid walking around after dark there. Public transportation is readily available close by to around the region.