The Drobo is a great unit, with flexibility that you can't beat for the price. That said, I have noticed that it is a bit slower than I expected. More critical than basic I/O speed, when the system boots up, it frequently takes quite a bit of time for my PC to recognise the drives as being present. I have my iTunes library on one of the volumes. When my PC boots up, I have iTunes launch immediately upon boot. Frequently, iTunes will launch before the drives are recognized, making iTunes error out. Not ideal.

Also, one little tidbit I wasn't expecting. For obvious reasons, when you start racking up the storage, you need to use separate partitions if you are looking to maintain Windows compatibility. I was hoping to split my storage into one FAT partition and one HFS+ partition (one for Mac and one for PC). Once you have chosen a partition type, all partitions must use it. No splitting the baby.