I just got my Drobo FS the other day and so far everything seems pretty good. Speed is decent with my MacBook Pro over my 802.11N network with my Drobo connected to my Airport Extreme Base Station.
I do have another question, though. For the sake of reducing clutter in the room with all my other computer stuff, router, modem, DirecTV, cables, cables, cables!!! I am thinking of getting a secondary Airport Extreme base station to act as a wifi bridge in my house. Would I see any performance issues if I connected my Drobo FS to that 2nd Airport Extreme router versus the one directly connected to the modem?