I'm looking to attach some storage to my RT-N66U, primarily for wireless media streaming and possibly for automated backups. I don't want to spend a lot of money -- less than $200 -- so my options are limited. I'm torn between getting a simple USB drive vs. spending a bit more to get a very basic NAS. I'm leaning toward a cheap single drive NAS, but I'm not sure what sort of advantages it will have over a USB drive combined with the router's built-in utilities. Advice and opinions much appreciated!