As far as, i know i dont think so its needed, but there are some case, where they say powerpath ve for managing multipathing with EMC storage its required on ESXI and also its licensed from EMC.
Thanks & Regards
Dharshan S
VCP 4.0,VTSP 5.0, VCP 5.0
It isn't required, but if you are licensed for it then I say use it.
Good Luck!
Brian Atkinson | vExpert | VMTN Moderator | Author of "VCP5-DCV VMware Certified Professional-Data Center Virtualization on vSphere 5.5 Study Guide: VCP-550" | @vmroyale | http://vmroyale.com