I also switched from Sibelius—albeit right when Dorico was first released. I do not miss Sibelius in the slightest. I liked Sib (and even the commonly abhorred ribbon!) but after the whole Avid debacle I was left with a bad taste in my mouth. As others have suggested, the switch will be shocking at first because the working paradigm of this program is totally different. The good news is there are LOADS of professional how-to videos on the Dorico YT channel (thanks Anthony!), there is now a relatively mature manual, and this forum is VERY active. Ask away here and someone will be sure to answer within minutes. It never fails, although people may warn you to search through old threads first. 
In the end, all I can say is that I love working with Dorico. I have had my days (especially in the beginning when I had to retrain my brain) but once you work out your patterns and learn where certain options live, you should be totally fine.