Create Storage Pools or not? 2 Member Equallogic group

I have a 2 member (FW 7.0.1) Equallogic group:

PS6110XS Raid6 accel. - 9TB useable

PS6110E Raid6 - 33TB useable

The environment is 100% VMware and client want to ensure cirtical VMs (Citrix etc) are running on known good I/O at any given time, Nothing fancy (eg Storage DRS is being used at the VMware level) however using MEM (MPIO) is available to us. Junpier 10Gb switch stack.

What are the opinions on create 2 storage pools Vs 1 storage pool containing both members? (and allowing the eq to tier from SATA > SAS > SSD as required)

I plan to create Volumes ranging from around 1.5TB up to 2.5 (not too few)

Thanks