no defragmentation program available knows where data is located on the nand. period. diskeeper and perfectdisk even state that all their 'ssd optimizers' do is consolidate free space at the file system level (you may have to dig deep to find this admission on their web sites!).
it's not necessary for anyone to spend money on a program to consolidate free space. windows 7 and probably vista can do just free space consolidation if you type 'defrag [drive]: /x' at the administrator command prompt.Those who do not want to spend the money on PerfectDisk or Diskeeper with Hyperfast CAN image their SSD, secure erase it, then restore it to consolidate free space once in a while.
even better, download a freeware defragmenter like defraggler or mydefrag, they can both do free space defragmentation only.