No, it's actually not similar. Don't get me wrong, AA makes great stuff, and if you want a more subdued sound, that would be a great choice.
The Borla is much more aggressive. People follow me until i park just to ask what I have under the hood (no joke). It is louder than the AA (almost too much so), but at speed it is virtually silent. It only growls under acceleration of decceleration.
If anyone is smart and can give me some suggestions as to how upload a video/audio clip of my exhaust, I would love to do so. I have unlimited resources for capturing devices (I was thinking of one of those E-wear things from Panasonic), I mean unlimited (I'm employed by a consumer electronics company and have all their products at my disposal).