I was not aware that quickpar did not regress directory trees, that's important for general use (ie, not as a quick file backup scheme but as an on-line data integrity checking program). As for the repair block size being 1/32768 that is much too large to recover bit errors (mulitiple bits being in error) even more so w/ enterprise drives. With some of the spatial data we've seen so far that sectors/bits that have errors are in close proximity to each other on physical media by using a large block group as that will not be able to recover the block when multiple bits are in error.