Drobo
Drobo is one of the more popular bulk storage options. Drobo comes in a couple of configurations that allow users to place their own drives inside the unit. In general, users that are using Drobo are looking for 2 TB or more of storage. Because of the nature of the configuration options, each Drobo is different, there is however a mixed debate about the product in general, much of that debate can be found in this thread. A Drobo v. alternative discussion was had here. In general, the Drobo has had positive reviews, but the discussion of the cases of failures combined with the price of the unit sways a lot of users to alternatives. User pprior attempted to switch to a LaCie alternative, but ultimately went back to the Drobo finding that the LaCie produced more noise. The one consistent thought seems to be that DRI (Data Robotics Inc., the maker of Drobo) replaces the drives quick and their customer service is good.
Forum Users Expressing General Support
gatepc, Cynicalone, frunty (unit failed, was replaced quickly and now is happy), whynot83706, DRI. geoffreak, UbuntuFu, pastrychef, Rich1963 & Zyniker
Forum Users Not So Happy
brand, blodwyn, pprior