Also a Finale user from Finale 3, and switched to Dorico. While it is not as intuitive, after working through a couple of their tutorial examples and a couple of projects I have gotten pretty good with it. In some things it is faster and easier than Finale. I disagree with the other poster about parts - I found that once I got the hang of it they actually came out cleaner and faster than with Finale (other than titles/subtitles/etc - that is a pain).

Never used Sibelius so can't compare. Biggest takeaway is that Finale and Dorico obviously came from two different bases. Finale was notation based since the beginning, while Dorico (Steinberg) came from the sound production world.