Been using SONAR since version 1.0. Really been very pleased with its capabilities and workflow. One thing that's big to me is that I've been a Windows user since 3.1, and SONAR works like Windows works (please neither take, nor insert any sarcastic comments on that), right-click does the options, CTRL + drag equals copy, etc. Super easy for a Windows user to grasp. It's also one of the few apps that's Windows only, so, again, it really lends itself to people who like PC's.
I also am quite comfortable with Cubase, Nuendo, Pro Tools, and Live. Each has their certain strengths, but SONAR seems to do the most things in the way I want it to of any of the apps.
Download a demo and try it. Highly recommended.