It's funny to me that I was using Sonar 8.5 for YEARS... never updated to any of the X versions because I kept reading how different and buggy they were, so it just didn't seem worth it when 8.5 was fine for my purpose. And I was on version 5 for a long time before finally upgrading to 8. I've never been a prolific songwriter, but over the years I completed a couple albums in Sonar 8.5 and I was happy enough using it except for one major bug that I just put up with.
Less than a year ago I finally took the plunge and upgraded to Sonar Platinum. It was really a huge improvement over 8.5, that huge bug was gone, and I looked forward to the updates every month. But as soon as I found out Cakewalk was shut down, Sonar felt dead to me, like hanging out with a corpse. I know that sounds like a bizarre overreaction, but that's how it felt. So I took the Cubase 9.5 Pro offer and have been enjoying learning that. There is so much to chew on in that program, lots of really cool features. For all I know at least some of them were available in Sonar too, but I never knew about them.
Personally I think Cubase is the most similar program to Sonar, at least in terms of the density of it and the richness of available features, and Cubase is expansive in some other areas that Sonar had never developed (I like that I can reasonably score a film in Cubase if I ever want to try doing that, for example). But maybe that's just in how I work with it. They are still very different programs.