See, here's where the different opinions come in. I know a few Sonar users that are very happy with it. When I was auditioning DAWs, they set me up with Sonar (Producer Edition, I think it was called) and it fell apart on my acid test.
That being said, my demands on a DAW are completely different than the average recording/mixing engineer would encounter.
I do remember Sonar's audio engine and summing being quite good, though... And, if I'm not mistaken, it had a cool Lexicon verb plug with it (Parthenon? Pantheon? Some Greek word with a "P") that sounded wonderful.
So, TRY stuff. Beat it up. Run it into the ground. Then, buy one and get to work.
JS