Not necessarily.The only reason to flash the BIOS to F8 would be if you have a Xeon CPU.
The F8 version is only required for the Xeon v2 processors.
from GIGABYTE - Motherboard - Socket 1155 - GA-Z77X-UD5H (rev. 1.0)
F7 = Improve system compatibility
F8 = Improve keyboard compatibility
The bios descriptions are woefully inadequate and include other undocumented fixes or enhancements.
Newer versions are usually (but not always) better.