I have one 32GB X25-E SSD and I upgraded it yesterday (to the latest), no issues:
Firmware Version: 045C8850
But do note, each step of the upgrade process takes 10-120 seconds, so be very patient and let it take its time.
Can anyone else please offer some advice?
Before put the drives in RAID upgrade the firmware. Follow Intel`s instructions. You can have better performance if you have the same version of firmwares.