"There are three mainstream high-end enterprise arrays; EMC's VMAX, HDS' VSP, and IBM's DS8000"
I wouldn't exactly class IBM as mainstream these days. They are a dying boat anchor vendor:
When their midrange business started being eaten alive by Wintel, instead of leveraging that ecosystem they tried to counter it with investments in Linux - which has been a massive fail for them. No one wants to keep the UNIX type Dev Ops legacy complexity that was part of the boat anchor model when given the chance to move away to a lower TCO, more modern and less complex world.