I'm wondering why Cisco recommends RAID 5 for the BE7H-M5-K9 model. I know there is a larger amount of space, verses RAID 10, for example, but the performance increases in RAID 10 over 5 is dramatic.
If we were to switch to RAID 10, is that still supported under the TRC?
No, the RAID is part of the TRC specs
If you choose to change it, you lose the TRC support level and go to UC on UCS spec based.
You'd need to ask your SE/AM to reach out to the team that is in charge of UC on UCS and UC virtualization so they can provide the technical answer and the reasoning behind that choice, assuming it's something they can share.