Okay. One feature I'ld like to see in Defraggler is support of NTFS reparse / junction points. I've only seen them supported in expensive software and in Microsofts own defrag tool until now.
To explain my point: with NTFS it is possible to "mount" NTFS partitions to empty folders, similarly to *nix. These partitions don't have to have an own drive letter in that case, but are still another partition. Thus, Defraggler can at the moment only defragment my system partition, but not my programs and data partitions, because they have no own drive letters, but are still used regularly.
If Defraggler will once support that, then it will really be my favorite freeware application (currently, it is Foxit reader).
But: Defraggler already kicks ass, I'm really impressed. Keep up the great work!