From my limited experience, it seems like a top-notch open source piece of software. If I recall correctly, it uses the cross-platform wxWidgets library, which is cool. I've used Audacity under Linux, but I'm guessing it's available for Windows and Mac also. Otherwise what's the point in using wxWidgets.
It seems to me that editing audio is harder than editing video, especially for longish files.
I've never used any commercial, "professional" audio software, but Audacity seems like the real deal to my naive self.
I just installed Linux Mint for the first time, so I'm off to experiment with recording audio with it. I want to record the local announcer here calling the BCS national championship game next month. If my team loses, I'll delete it immediately. But if we win, I'm going to download the video of the TV broadcast, and use Cinelerra or something to replace the audio with the homer. :)
In the past, I've had luck using simple command-lines to record audio, eg:
arecord -f cd -t wav -D copy file.wav
But that wasn't working so well in Ubuntu 11.10. I ended up with a big file of static. I never could nail down what the problem was. Hopefully, I can get it all sorted out soon.
Good luck!