i have a 500gb AAKS drive and its very quick, the YS drives are the newest models to my knowledge and they are designed more specifically for RAID systems in that they are more reliable and stable according to the pages in OcUK the latter "RE2" drives do support NCQ.
I myself am interested in 2 of these 500GB YS drives and configuring them in RAID 0 and using them as storage drives. havent completely decided weither i trust 100% to put all my data and media files on them though so have been investigating Network Attached Storage as an alternative, but it seems these dont perform as well transfer wise as i had previously thought.