I use Sonar since Sonar 4.
I don't actually know the others DAW, though i read forums and reviews for years.
But i looked (a quick look) to Steinberg and Digidesign sites, watching for issues reports and updates, and i found a lot of stuff (for example, Cubase 6.5, 6.5.0, 6.5.3, 6.5.4).
So, i wonder if it is not the same way for all the existing daws (upgrades, issues & bugs, patches, and so on).