Best set up for iTunes and My Book Live?

Hi,

I recently purchased a 2t Mybooklive to use as network storage to make my media accessible to various devices around the house. I’ve put my library of video files on there and have them playing HD quality quite happily to my rasperryPi and streaming to my ipad through the WD app. 

I have also transferred my iTunes library to the drive, but unfortunately with less success. When trying to play a lot of the files is lags momentarily before starting playing. For some of the larger file if lags even longer, but for unknown reason some smaller files it just seemed to send iTunes into a permanent confusion and the app locks up. Then I got to adding new media to the library and editing it’s tag info and artwork. Adding files is fairly slow, editing them is ridiculously slow. Previously, when I was using my WD USB drive as the host for my library, this was all fairly instantaneous. But now it editing the mp3 information locks up iTunes and takes about 5 to 10 mins to edit a single mp3 file tag.

Sorry but that kind of performance renders this drive completely useless to use as for iTunes library storage. Yet it is sold as such. Am I going wrong somewhere or is this actually the best WD My Book Live can do?