I'd happily
buy at $99 every year, but will never subscribe. Subscription implies that I can use the software for a year, after which time it becomes useless/locked. It could also imply that my PC will be expected to "phone home" to verify that my subscription is current. There's also a chance that we'll be 'forced' to update software on their schedule, what if I end up liking the next version so much that I want to use it for years and years?
Furthermore, I've tried to "opt in" to these e-mail alerts numerous times before, a problem for many of us share. I find it rather bold of them to even suggest/imply a possible subscription model when they can't even manage to send a batch e-mail correctly.
Now, that is all just wild speculation at this point. But needless to say, if any of the above turns out to be correct, then I'm unfortunately going to have to part ways Sonar. One of my deciding factors in going with Sonar years ago was the overall "ease of ownership".