I was in need of an external array and wanted something with ability to expand on the fly. I knew of the Drobo devices and they seemed to do what I wanted - on the fly expandability and two-drive redundancy (two out of 5 drives can fail without data loss). I opted to go with the Drobo FS - a NAS device with gigabit ethernet connectivity. I planned on (and did) putting the whole thing in the network closet so I didn't have to hear it making noise in my home office. I was expecting a lot of noise from the 5 drives plus power supply and fans, but it's actually surprisingly quiet. My experience with network drives has been with reasonably fast servers at work (serving hundreds) and my Time Capsule drive and a USB drive hanging off the Time Capsule. And file sharing from Mac to Mac at home always seemed quite zippy for network storage. So I figured the Drobo FS should be acceptably fast. I did my due diligence and looked up some online reviews, too. They were getting around 25MB/sec peak throughput. Good enough for me I thought. Ordered a bare unit and put in some old drives of various sizes I had lying around, totaling around 1.5TB. Started putting it through it's paces. It was no speed demon, but fast enough I thought. So I ponied up for 5x 1.5TB Western Digital HDs and configured the 7.5TB Drobo for dual-drive redundancy and configured a couple of volumes totaling 4.08TB of redundant storage. I was quite happy. Then I began using it in earnest... This thing is so frustratingly slow that I want to toss it out my window. It'll peak at 25MB/sec or so for single, large, contiguous transfers. But file-to-file seek is so ***** slow that its transfer speeds can be measured in 10's of KB per sec when accessing a cluster of small files. I had analog modems on my Apple ][+ that were faster than this. I've done the trouble shooting, swapped drives, changed networking configs, upgraded its firmware, but it's just that slow. Even connected it right to my Mac with a crossover cable. Same. My Time Capsule is an order of magnitude faster. Even the USB drive hanging off the Time Capsule is faster at network transfers. I should sell it, but I don't wish this level of pain on anyone else! So, fair warning - stay away. I cannot recommend this product to anyone. ** TL/DNR: Drobo FS massively sucks. I'm bummed and out $600. Currently looking at this: http://eshop.macsales.com/item/Other World Computing/MEQX2KIT0GB/ Any one use one? It's not hot-expandible, but it'll at least be fast.