Audio Converter & Mixer is a multimedia application which joins together different audio files and converts the output into a WAV file. It supports audio files such as: MP3, WAV, AC3, OGG, MPA, MP2, AIF and it can extract audio from video files such as: VCD, MPEG, AVI, WMV, ASF, OGM, DIVX, DAT, SVCD and creates CD quality WAV files.
Drawbacks / flaws: The output is restricted to only WAV files, and WAV files take too much space, so you need an extra mp3 encoder in case you want your outputs to be encoded as mp3s.
Pluses: No matter what compression rate, sample frequency or channels of input audio are, Super Sound Joiner converts them to same parameters and output into one WAV.
In conclusion: Easy to handle, fast and compact, but some extra options would do no harm.
