Yev here - it's interesting, we don't really chat about that often - what I would do is get the least expensive drive that has the most capacity and make sure the NAS is backed up somewhere in case of failure or theft. Personally I think the Toshiba drives are pretty good, but Seagates are affordable and do a good job. Plus there's always HGST which are rock-solid, but tend to run a bit more expensive.