I am presently running a Drobo S over Firewire 800 on my new cylindrical MacPro running Mavericks 10.9.5. The Drobo S is a 5-bay unit and I have almost filled it up with data. I have five 4TB drives in it now. I am stuck on deciding to move to a DroboPro 8-bay unit that connects using Firewire 800, or go with a standard RAID 6 8-Bay thunderbolt enclosure. Pros and cons for the Drobo: Pro - It is dead simple and I've never had a problem with the three Drobos I've owned. Con - the maximum volume size is 16TB. Once you put more data than that on the drives it will create a 2nd volume. I only want one HUGE volume. Pros and Cons for the traditional RAID 6 8-Bay enclosure: Pro - I can RAID 6 all 8 drives into one Huge volume, formatting with HFS+. Pro - Faster transfer rate. Con - The redundancy takes a lot more space than the Drobo. I think that about gives you the big picture. If I've spoken out of turn, please correct me! I'm using this for my massive iTunes library which consists of over 4500 Movies, 200,000 Songs, 5500 TV Shows, podcasts and 110 Video Training Courses in iTunes U. I need just one massive volume because iTunes will only let you locate your iTunes library in one location. Any help and insights into my dilemma would be greatly appreciated! Thanks for your help!