Re: If money was no object...
Density is an issue...? Can only daisy-chain so many drives on a single SAS card before you notice a serious performance decrease, and a server chassis can only hold so many disks... Even the highest density I would only be looking at 48 to 72 bays for 2.5in disks, but with 3.5in disks, though I can only pack about 48 tops into a rack, would provide far higher capacity. Maybe when SSD capacity can catch upto HDD capacity, or at least get to 4TB per disks.
Now I could go with a new Hybrid-Array that uses an SSD as a super-massive cache (imagine a 1TB cache, or larger) for the HDD RAID Array, that would give the performance someone you would desire, but give someone like me, most all the capacity I would desire.