Hello, the same problem on Z87 chipset motherboard. Configuration: 1 SSD, 4 HDD in RAID (Matrix: first volume RAID0, second one - RAID 0+1).
I've made update of SSD firmware and all HDDs firmware to the latest versions, I've manually made update OROM and EFI RAID "Sata driver" to version 12.7.0.1936... (I've also tested OROM 13.0.1.2030 version - the issue persists) Under Windows 8.1 x64 power off issue persists: ( spin down -> spin up -> spin down) with all versions of RST Driver, later 12.0.0.1083 (is OK) (included in windows version 12.0.1.xxx is OK).
However, version 12.0.0.1083 has the same spin up/spin down issue as later versions, when computer go to sleep. I've also disabled hibernate via powercfg -h off - result the same, issue persists.
Of course it's not big problem, just small issue and does not prevent normal work, but hope and belive in Intel team! )
P.S. I do not wand write brands in public, but if you need, I can send detailed hardware and firmware information in private message for testing/reproducing purposes.