I used Finale for several years, then in '03 switched to Sibelius. It was, and still is, a fine program. The management of the program by Avid has been a disaster, so I was keen to follow the developments of Dorico. I switched over to it last summer, and I haven’t looked back. Yes, there is a learning curve, and yes there are some things that each one of us would like to see implemented. I would just say this: if Dorico can produce the type of score you need, then it is indeed worth looking at very seriously; if you have the type of score that can’t be done, then wait. There is a lot to learn, but once you get the hang of it, things move right along. I really only open Sibelius to export older scores.
The other advantage to Dorico - I think, but I am not a programmer - is that it is built on a new chassis. Its “ground up” is new, whereas Sibelius and Finale are bolting on new features to a frame that was constructed a long time ago (at least thinking in “software years”). This will allow the program to grow/change/adapt more nimbly than others going forward. For myself, I wanted to hop on the new train before it got too far out of the station…