Unfortunately my GNU/Linux box is a PowerPC and I had the privilege of finding all sort of strange Fluendo bugs... but apart from bugs, the gstreamer0.10-fluendo-mp3 plugin consumes much more CPU (about 22% against 7%) than the standard mad plugin for gstreamer (found in gstreamer0.10-plugins-ugly collection) and fluendo-mp3 is licensed under the MIT license while the mad library is instead GPL. Last but not least, I've no data to show that but it seems to me that also the audio quality is better with mad!
MAD better than FLUENDO on PPC!