We're going to do 5 days in Copenhagen in May 2019. We're 60, and are all about walking and gawking, casual eating and drinking, and wouldn't dream of any travel mode but mass transit. With that sweet 5th night free, the Copenhagen Marriott is 160,000 points and the AC Bella Sky is 120,000. Both are rated Very Good or Excellent by about 90% of reviews on TripAdvisor. The Marriott is right next to Tivoli, but that's just one day of the visit, so not critical. Walking 4-5 miles per day is the norm for us, but we often double that touring a great city.
The question - is the Marriott worth 40,000 more points than the AC Bella Sky?
Edit: Thanks to all, I think we'll go with the Marriott, based on being right in the middle of it all...and free beer.