Superb. Very simple to use with superb Graphic interface. Only lacks more preset files, volume up/down slide bar if 'vol' or 'volume=' switch is used and Nominalize rotary button (maybe utilize the famous mp3gain utility or do it internally). This is not for the beginner as ffmpeg switches are used throughout and some knowledge is required. It does lack a good up to date User Manual which should also include many preset examples for novices to use it. It has not been update for quite some time now. That said, its one of best I have seen in a long time and well worth having.
The best converter!!!