and NAS no Disk cache software.... and no real time virus protection ,i don't know why u like nas.. but i think its wasting of money maybe u r just new in bt.. so u like it... i am using bt for over 3 years... i tried many bt software... the best one i think its from JAPAN , its called bitcomet GHOST 1.04, its much faster , someday if u have time, please try it.