This review 
http://www.krazyworks.com/gadget-review-dlink-dns-321-nas/ recommends NFS over Samba.  It claims NFS and FTP is alt least 20% faster than Samba.  I enabled NFS and ran NASTester 0.4.  The result was actually slower than Samba.  Does anyone get better transfer rate with NFS?  BTW.  Is FTP faster than Windows's copy&paste (FireFTP cannot handle files bigger than 2 GB).
Thanks,