Hi,
IMHO the "S-class" Buddha is pretty good - I got mine mainly for the Catweasel part, and having the ability to add a cheap and large standard IDE drive is even more of a bonus.
On my A3K, the speed of the IDE drive "feels" faster than the SCSI drive I've got connected to the internal SCSI controller - but that may be due to the SCSI drive being a bit of an old clunker!
- Ali