>Another thing you should do is defrag the drive after you convert it. FAT is notorious for wasting disk space and you won't really reclaim it unless you defrag all the files.

Defragging NEVER recovers wasted space. Defragging makes files access faster by placing the file's data in adjacent clusters. This reduces seek times on the disk. The place where FAT wastes space is in the last cluster allocated for the file. This is because the cluster is the minimum allocatable unit of disk storage. Wasted space for a file is cluster size minus the size of data in last cluster for file (eg. 32k cluster - 1K file = 31K waste) FAT clusters are commonly 32k or even 64k on large drive and NTFS clusters are commonly 1/2K.