Graphic Design Storage Server

Greetings Fellow Admins,

I'm currently researching an upgrade to our existing 10TB Direct Attached Storage solution for hosting JPGs and other graphics files used to build publications. The solution must be able to server graphics files (JPGs, PSDs, INDD's) at high performance read / write speeds.

I'm not as concerned with with being able to expand as I am with serving files at highest read / write speeds possible.

Any experience here? Which is better, iSCSI or DAS?