I have a Drobo. 4-bay FW-800 model.
Had it for about 18 months now. The ability to plug in larger disks without moving the data somewhere else first and re-RAIDing is brilliant.
I did have some issues with volume corruption, but this turned out to be due to me unplugging or switching it off without ejecting the drives first. Once I made sure I ejected it every time, things have gone brilliantly.
It is a little noisy due to air movement, though nothing that will disturb music at even low volumes.
I tend to use it as a backup device, though if I was using it as a primary/scratch drive I would have the data somewhere else. Same goes for any device. Data is priceless in a lot of cases.