When configuring a VNX now eMLC drives are an option for FastVP! We can really drive an insanely competitive solution using both types of Flash now. This is critical in competitiion against the various start ups. Many of them only leverage the eMLC drives and have no option for SLC.
Build a solution using SLC for FastCache and then eMLC for your FastVP tier (remember you do need a spare for each) then 10K drive (I prefer 10K from a $/IO over 15K) backed by a pool of NL disks leveraging block Dedup. This allows you to leverage the compound efficiencies of our platform to not only be cost competitive ensure that your proposed solution out performs competitive plays. For icing on this flash cake consider seeding a customer with XtemSF/SW XPacks as well. Positioning flash at every layer shows a depth no other player can match.