Having used Toast 19 Pro for a few days now, I thought I would share some thoughts on experience. I was going to leave a star rating, however there doesn't seem to be an option for it, simply a comment option.
Anyway I own a license for Toast 6, 8, 11, 17, and 19. Toast 17, and 19 are both pro licenses.
I started using Toast 6 when I had my blue and white G3, and it was a good reliable burning solution back in the days when Apple was picky about what third party drives their native burning supported. Since then: I've upgraded to new releases every few years to see what's new, and to have a current copy around. I will skip my experience with 8, and 11 because that was too long ago to be relevant for today. I'll focus on 17, and 19 here.
I bought 17 when Mojave was the current OS. Overall it worked and didn't have that many problems. The UI was pretty clean and worked well, too. Fast forward to a couple days ago when I purchased 19 pro. I wanted to see how it was performing under Big Sur as the
current OS. I have to say looking back, over my older version of toast and running them in various macOS VMs to test performance: Toast 19 really has the most polished UI for the most current release of Toast, and macOS. With the exception of toast 8, and 11 (6 isn't even an option here.) 17 has weird graphical glitches on some of it's menus, especially on older version of macOS prior to Mojave, and Catalina. 17 can also be somewhat slow to load on certain operating systems while 19 loads reasonably fast. All the tasks I would normally perform work in all current version I've used, but I would say when it comes to authoring, and burning, and a nice overall UI I think the latest version of 19 is the cleanest and most optimized compared to older.
I would still like some professional options for disc authoring for the Mac, but toast has worked well. for personal use. The Pro stuff would be more for if I was doing more for other people I would like to be able to tell them it was professionally done, especially since I have education, and some experience with pro production. From what I have found out though from talking to others who do professional work in media, a lot of tools (depending type of work) are now on PC only, which is fine as long as switching to windows, or even Linux would give me a better advantage over the Mac these days.