I own an original Drobo and am quite happy with it... but I don't think it's right for your needs.
I looked around for a while and there's nothing else that does exactly what the Drobo does - they fill a niche very well. But they're relatively slow and can be noisy. They're fine as a backup device or for low-bandwidth applications but I wouldn't recommend one to play media files from- the 4-drive model that I have is simply not fast enough. Perhaps the newer models are significantly faster, and although I think they're too loud for a bedroom they're probably no louder than any other multi-drive enclosure, so YMMV.
There are a few stories on the net from people who have had disastrous problems with theirs. I looked at these very closely before I bought mine. Mostly they're from individuals who make a lot of noise in order to get attention, some of whom had done really stupid things to cause their own problems (eg if you have a 4-drive raid, and one drive fails, don't update the firmware on the other drives while the raid is rebuilding...) Some of the other stories were the results of Seagate firmware issues that affected many products and manufactures, not just Drobo. Having worked in video production for almost 15 years with all sorts of RAIDS, NAS and SANs, the Drobo is no worse than anything else out there and seems to have lots of happy customers.
But the older models are really quite slow.