I've used its python bindings. I've been quite pleased with how well it works, honestly. I wrote some software for a client with multiple radio stations. It's a service that listens to one web stream per station and shoots the client an email/text if it detects problematic audio (e.g. static, silence, etc.). Some of the stations are talk and others are music, so it needed to be robust. Aubio made it really easy to test different detection algorithms, and its documentation was tremendously helpful. IRC room was active as well when I had questions.