is this a good deal? never had a NAS.
With Drobo you pay a bit of a premium (over equivalent capacity/features) for ease of use / setup (think "Apple").
Technical geeks will tell you all kinds of wonderful things about other NAS devices (many good ones out there) or reasons to not like Drobo, but if you are new to NAS and you don't want to bother as much with the nitty gritty details, Drobo is a good choice.
Speed was an "issue" (depending on your needs/wants), but the 5N was to have significantly improved that and is the main point behind their new release.