I do prefer Synology over Buffalo though.
HW wise, the main argument for synology over buffalo here in Italy is if you use a NAS as a primary file server: no Terastation 5000 has redundant powersupply, nor easy maintainance is allowed on site. If power suppl. blows: byebye data, you are KO for a couple of days.
(also buffalo do not provides units populated with 8TB disks (not yet... hell 8TB in a single disk, brrr))