Emphasis is on failure-safeness and ease of use.
Jack can encode multiple tracks at once, good on SMP systems. It can resume its work if interrupted, can schedule encoding in reaction to system load and keeps an eye on available HD space. Freedb query is also supported, any time you like, even after encoding. Jack can try to query freedb for MP3s of which you do not know the CD anymore, provided you have a complete rip and know the track sequence. No dependencies filed.